Thunder ValleyRegenerativeDevelopmentPER SubmittalApril 2, 2015

Thunder Valley Community Development Corporation Applicant Porcupine, SD

KLJ Engineering Civil Engineer Rapid City, SD

BNIM Planning and Architecture Kansas City, MO

Pyatt Studio Planning and Architecture Boulder, CO

DESIGN TEAM

ContentsProject Planning 1 Location 2 Environmental Resources Present 4 Population Trends 5 Community Engagement 7

Existing Facilities 9 Location Map 10 History 11 Condition of Existing Facilities 12 Financial Status of Existing Facilities and Water/Energy/Waste Audits 13

Need for Project 15 Health, Sanitation, and Security 16 Aging Infrastructure 18 Reasonable Growth 19

Alternatives Considered 25 Water Supply 26 Waste Water 36 Stormwater 52 Roadways 60

Selection of an Alternative 71 Water Supply 72 Waste Water 76 Stormwater 80 Roadways 84

Proposed Project 87 Preliminary Project Design 88 Project Schedule 92 Permit Requirements 94 Sustainability Considerations 95 Total Project Cost Estimate 96 Annual Operating Budget 97

Conclusions and Recommendations 101

References 105

Appendices 109

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Project Planning

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Location

The proposed 34 acre Thunder Valley Community is located ¼ of a mile north of Sharps Corner, in the Porcupine District on the Pine Ridge Indian Reservation in Shannon County, South Dakota.

The legal description of the property is Parcel 1: Lot 1, being a portion of Tract A of the SW1/4 and SE1/4 of Section 34, T.40N, R.43W, 6th P.M., Shannon County, South Dakota and Parcel 2: Lot 2, being a portion of Tract A of the SW1/4 and SE1/4 of Section 34, T.40N, R.43W, 6th P.M., Shannon Country, South Dakota.

The site is bounded on the east by Bureau of Indian Affairs (BIA) Highway 27, to the south, north and west by agricultural pasture land. Additionally, an unnamed tributary to Porcupine Creek is adjacent to the site along the southern boundary. The northern portion of the site drains northeasterly while the southern portion drains southeasterly into the Porcupine Creek tributary, while site elevations range from 2940 along the west boundary to 2885 near the northeast corner.

Today the site features a temporary modular office for the Thunder Valley Community Development, community garden, tool shed, and Native American Sustainable Housing Initiative (NASHI) prototype home.

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South Dakota

United States

Thunder Valley

Pine Ridge Indian ReservationFIGURE 1 NATIONAL CONTEXT

FIGURE 2 LOOKING WEST FROM NORTHWEST CORNER OF SITE

FIGURE 3 LOOKING SOUTHEAST FROM NORTHWEST CORNER OF SITE

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Environmental Resources Present

Of the 34 acre Thunder Valley site, the eastern 18 acres is currently comprised of dry land row crop, while the western portion is native pasture grasses. Since this proposal will convert land to non-agricultural use and is being completed with assistance from a federal agency, it is subject to the Farmland Protection Policy Act requirements to consult with NRCS on the proposed project. The state NRCS office has found that no important farmland will be impacted by this project.

where proposed construction will disturb the site, which is essentially the entire project area.

If special status species under legal protection are found during reconnaissance surveys, OST Parks and either the US Fish and Wildlife Service or South Dakota Game, Fish and Parks agencies will be contacted. If special species are found, the US Fish and Wildlife Service, USDA Rural Development Service, South Dakota Game, Fish and Parks and Thunder Valley CDC would then a develop a binding agreement to reduce, avoid, or mitigate impacts to special status species under legal through the following types of measures:• Avoidance (for example, through re-designing

the alignment of pipelines, or timing of construction)

• Construction methods and monitoring by trained crews (for example, prepared to halt construction upon observation of endangered species)

• Mitigation (for example, thorough creating or restoring habitat with den sites on another suitable location on the Reservation).

The proposed project site is not located within a documented 100-year or 500-year FEMA Flood Insurance Rate Map (FIRM). However, the unnamed tributary’s floodplain along the site’s southern boundary was studied as a class project by the Oglala Lakota College and is therefore shown on the project site plan. Buildings are proposed out of and above the floodplain boundary.

The above and following is an excerpt from the Environment Report completed in 2012. See attachment 1 for full report.

An unnamed tributary to Porcupine Creek is located along the southern portion of the property (approximately 3 acres), where riparian habitat is found. The tributary is a shallow dry creek flanked with riparian vegetation such as chokecherry, native plumb, rubber rabbit brush, silver sagebrush, buffalo berry, and redroot scurfpea. Riparian trees primarily include cottonwood. Please refer to the Thunder Valley Environmental Report for additional information regarding wetlands/soils, endangered species/critical habitat, floodplain, and historic sites.

Consultation with the US Fish and Wildlife Service has determined there is no critical habitat on the Thunder Valley property. Consultation with the Oglala Sioux Tribe Parks Department confirmed there are no known occurrences of special status species on the Thunder Valley property. However, it is Thunder Valley’s intent is to conduct a pre-construction reconnaissance survey with OST Parks and/or other biologists on the fallowed farmland of the Thunder Valley property, to protect special status species which occur in the broader countywide area and whose habitat associations are matched by the habitat in the location of proposed activity. The survey will be conducted

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Population Trends

The resident population residing within the jurisdiction of the Oglala Lakota Nation is approximately 30 thousand with thousands more enrolled members living off reservation homelands. Sixty-five percent of the population of the Oglala Lakota Nation is under the age of 25 years old making for a youthful and vibrant population.

Because of the paucity of standard housing and economic data available for Pine Ridge, researchers have attempted to gather data from multiple sources to cross-corroborate findings, including data from a proprietary source (ESRI) and findings from several studies of Pine Ridge, primarily from Colorado State University professor Dr. Kathleen Pickering’s work. Because federal allocations are based on population, knowing the number of residents on the reservation is a crucial piece of information for nearly all else that happens on Pine Ridge.

Like most federal agencies, HUD requires accurate population data from the US Census Bureau to ensure adequate funding for needed housing programs. Unfortunately, Census population numbers for Pine Ridge fall far short of the probable reservation population. HUD recognizes this shortcoming by allowing tribes to challenge all of the data inputs into the IHBG formula, including the Census, and HUD’s formula data reflect a more enlightened and accurate reservation population count.

Where a population denominator is needed for calculations, the HUD formula number from the same year as that of the other source data in the calculations is used. This is used because it is the basis for HUD funding allocations, it comes closest

The following is an excerpt from the Regional Equity and Opportunity Assessment prepared by The Kirwan Institute for the Study of Race and Ethnicity at The Ohio State University, and Policy Link. (see attachment 2 for full report)

While Oglala Lakota participants in multiple surveys and planning exercises identify housing as one of the most urgent needs for a young and growing population, data related to Pine Ridge population and housing needs are difficult to come by, whether the source is on the reservation or off. Even the question, “how many Native American people reside on Pine Ridge?” has multiple answers, depending on the source of the estimate. Data on businesses operating on the reservation are equally difficult to come by. Not having reliable population and business figures contributes to the challenges facing the community. It is clear that the population is growing on Pine Ridge, with conservative Census estimates documenting a 21% increase in population between 2000 and 2010. In comparison, the State of South Dakota experienced population growth of 7.8% between 2000 and 2010. The growth of population on Pine Ridge (and other tribal lands) also sets the area apart from the State of South Dakota, which has an aging population and is not growing as quickly.

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to the independent estimates arrived at by the Colorado State research, and it strikes a balance between the cited extremes.

Paul Iron Cloud, Chief Executive Officer of The Oglala Sioux (Lakota) Housing Authority, testified on the poor quality of reservation Census data before the Committee on Indian Affairs:“I would be remiss if I did not also mention that if a GPS and GIS needs assessment requirement was to replace the current defective U.S. Census method in the NAHASDA [Native American Housing Assistance and Self Determination Act] program, tribes, Congress, OMB and HUD would also then have an accurate, reliable and efficient way to better manage federal funding.” Recommendations to support accurate population data: • Support the recommendation in the Oglala

Lakota Regional Plan for Sustainable Development for the creation of a regional or tribal planning authority that acts as a one-stop shop for data on the Pine Ridge Indian Reservation. This entity would collect and evaluate data on an on-going basis.

• HUD should advance its work with the tribal housing authority to establish an accurate assessment of the Pine Ridge population and housing needs, and push other federal agencies to adopt the locally sourced numbers for use in funding allocations.

• HUD can advocate for more accurate data collection methodologies on reservations, including Pine Ridge, by leveraging the Congressional mandate behind the national assessment of Native American tribes to keep the need for accurate data before Congress and other federal agencies, particularly the Census Bureau.

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Community Engagement

The community impacted by this development is defined as the Pine Ridge Indian Reservation. Thunder Valley CDC has been working with the Oglala Sioux (Lakota) Housing Authority, HUD, USDA, reservation-based nonprofits such as Mazaska, and Oglala Sioux Tribe Partnership 4 Housing to develop an appropriate housing plan to respond to the needs of this regional community, including factors such as affordability, programs to prepare individuals to be mortgage-ready and financially literate, and the design of highly efficient, quality structures that are appropriately sized for many different family types.

geographic vicinity of Thunder Valley about the development of a community that nurtures positive change through connection to native identity and culture. This group of interested community members and potential partners has come together on four occasions in 2013 and 2014 to work on the planning, design, sustainability measurements, and engineering solutions for this Model Community.

During the years of 2010, 2011 and 2012, Thunder Valley CDC conducted a Regional Planning Process for the Pine Ridge Indian Reservation – The Oglala Lakota Plan | Oyate Omniciye’. Thunder Valley CDC facilitated many community conversations which included input from children to elders, elected officials, community leaders and those vested in building healthier and more sustainable tribal communities. This collaboration of committed citizens, organizations, tribal and outside agencies took an in-depth look at existing systems affecting the everyday lives of those living on the Pine Ridge Indian Reservation. Gathering information, creating outreach, and facilitating discussions about the future created the momentum to have an honest and collective conversation about the challenges our tribal communities face. In October of 2012, the Oglala Sioux Tribe adopted into law, Oyate Omniciye Oglala Lakota Plan as the official Regional Sustainable Development Plan of the Oglala Sioux Tribe, and one of the primary initiatives of the plan is the creation of Model Communities.

Parallel to the regional planning process, Thunder Valley CDC has been moving forward on their Model Community plan. Specific visioning and listening meetings were held with those in the

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Existing Facilities

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Location Map

FIGURE 4 LOCAL CONTEXT MAP

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History

There are existing facilities near or adjacent to the development, however they are owned by other entities. The Oglala Sioux Tribe (OST) Rural Water System has an existing 8-inch PVC water main that is adjacent to the site’s eastern boundary along BIA 27. The main was constructed as part of the larger Mni Wiconi Water System. The remainder of the site is undeveloped.

Approximately 1,500 feet south of the site, at the southeast corner of BIA 27 and BIA 2, are primary and secondary wastewater lagoons serving the seventeen homes at Sharp’s Corner Housing controlled by the United States Indian Health Service (HIS), see Figure 4: Local Context Map. The 8-inch OST Rural Water main was constructed in 2000 as part of the Mni Wiconi water system. The Sharp’s Corner Housing lagoons were likely constructed in 1973 when the homes were constructed.

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Condition of Existing Facilities

secondary cell. The primary cell is approximately 8 feet deep with an area of 29,000 square feet with a treatment volume of 560,000 gallons. The secondary cell is approximately 6.5 feet deep with an area of 62,000 square feet with a treatment volume of 1,445,000 gallons. Assuming five people per home and 100 gallons per person per day (gpcd), the 17 homes at Sharps Corner will generate 9,000 gallons per day. South Dakota Department of Environment and Natural Resources (SDDENR) requires 180 days of storage with a discharging lagoon system, therefore 9,000 gallons x 180 days = 1,620,000 gallons, consequently the two cells are able to capture the existing flows with a surplus of 385,000 gallons.

The current 5-day biochemical oxygen demand (BOD5) loading rate was estimated using the SDDENR loading rate of 0.17 pounds (lbs) of BOD5 per 100 gallons. Sharps Corner Housing will generate approximately 15 lbs of BOD5 per day. The maximum BOD5 loading rate allowed on the primary cell is 30 lbs per acre; therefore the Sharps Corner primary lagoon can accommodate approximately 20 lbs of BOD5, which is slightly more than the inflow. Consequently, the primary lagoon can accept approximately five (5) additional homes prior to maximizing BOD5 limits.

Aerial photographs of the site indicate large seasonal fluctuations in water level and vegetation growth below the high water mark. Based on these two factors and knowing the lagoon was constructed in 1973 it is reasonable to assume that the lagoon is exceeding the exfiltration limit. Any future use of these cells will require substantial rehabilitation.

The 8-inch OST water main is in good condition and suitable for future use up to approximately 75 years based on publications by Uni-bell. The OST Rural Water system is maintained and monitored according to the latest Clean Water Act requirements and provides safe drinking water to the area. In 2012, the water system met all Federal and State drinking water requirements. OST Rural Water is able to allocate approximately 125 gallons per minute (gpm) to Thunder Valley Community, however the OST Rural Water system is not designed to provide fire flows. Consequently, when fire flows are required within a community or housing development, a storage tank is constructed that is connected to the OST Rural Water system. (A storage tank is not proposed in this PER for Phase 1 of Thunder Valley’s development.)

The existing Sharps Corner Housing lagoons are earthen man-made structures with bentonite lining that are comprised of one primary and one

FIGURE 5 AERIAL OF SHARP’S CORNER LAGOONS

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Financial Status of Existing Facilities and Water/Energy/Waste Audits

The existing 8-inch water main is owned and operated by OST Rural Water and funded by the United States Bureau of Reclamation. Currently, water users within the Pine Ridge Reservation are not charged for use of the water.

The existing Sharps Corner lagoons are owned and operated by the United States IHS, and the residents of Sharps Corner Housing are not charged sewer rates.

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Need for Project

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Health, Sanitation, and Security

A broadly agreed-upon imperative is the immediate and significant need for housing and economic investment on Pine Ridge Reservation. While there is a lack of standardized data to adequately assess the need, one credible source, a 2013 survey of Head Start / Early Head Start families, indicated that top issues impacting families were “housing, death of a family member, and unemployment (about 30% responded equally to these three topics).” Given the stress, poverty and poor health engendered by difficult living conditions, life expectancy is far below that of US averages. For example, a 1997 study found that men on the Pine Ridge Reservation live 16-1/2 years less than average US males; women on the Reservation live 13-1/2 years less than average US females.

families alone of approximately 2500 new homes. All sources point to a demonstrated, significant need for additional housing units at every income level, including the replacement or renovation of current stock. While exact numbers are difficult to pin down due to varying population estimates, the Kirwan Institute calculated the minimum number of additional housing units needed to house the reservation’s population at 875 three-bedroom homes, an increase of 21.4% over existing housing stock.

Not only are there too few units, much of the existing housing stock is substandard and in need of repair. Nearly 70% of all reservation housing is HUD housing or a trailer home. The median home value on the Reservation is $25,900—barely more than one-fifth the US average of $119,600—the depressed values are due to the substandard quality of the housing stock and a lack of a widely accessible housing finance system for tribal land holdings. An EPA report on black mold in Pine Ridge housing states that mold has been found in 75% of tribal housing units, resulting in substantial health risks. Currently, the Housing Authority has inadequate inspection capacity; and while current housing resources are directed at mold remediation, the level of resources is insufficient

The above and following is an excerpt from the Regional Equity and Opportunity Assessment prepared by The Kirwan Institute for the Study of Race and Ethnicity at The Ohio State University, and Policy Link. (see attachment 2 for full report)

A 2010 UN report:“During the mission, the Special Rapporteur observed many families living in subsidized housing units in conditions of severe overcrowding. This was...most strikingly on Pine Ridge Native American Reservation, where it was described as commonplace to have three to four families living in a three-bedroom house. The conditions in the houses on the Reservation were the worst seen by the Special Rapporteur during her mission, evidence of the urgent and severe need for additional subsidized housing units there.”

The 2012 Oglala Lakota College Case Statement reported that students on the reservation in grades 3 – 8 average only 22% proficient in reading and 14% proficient in math. Clearly, for the health, education, and future of Lakota youth, housing must be stabilized and education, training and employment opportunities expanded. In July of 2013, the OSL Housing Authority estimated a housing shortage for low-income

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to address the scale of mold issues found. An additional challenge is the lack of places to house residents as renovations of their homes are taking place, (and lack of quality structures to provide storm shelter in regularly occurring extreme winter weather events.)

Reservation housing choice is currently very limited, due in part to the need to maintain existing stock and provide base-level shelter in the face of capacity shortages. And while current subsidies are directed at addressing the needs of low-income households, the reservation also lacks housing that would appeal to young Native American professionals (trained on or off the reservation) who would like to live on the reservation, but cannot. HUD and USDA are currently exploring ways to expand other housing assistance and development programs to Pine Ridge, such as the Section 502 Housing Loan Guarantee program that serves households earning up to 115% of median income, that can serve a broader spectrum of tribal members’ housing needs, and that can leverage more private resources into housing development.

In addition to meeting housing needs, home construction would also contribute to the overall local economy. The National Association of Home

Builders reported in 2009 that “the estimated one-year local impacts of building 100 single-family homes in a typical metro area include $21.1 million in local income, $2.2 million in taxes and other revenue for local governments, and 324 local jobs.” Even though these figures do not reflect the specific economic state of the tribe, this is an area of great potential benefit.

END OF EXCERPT

Not only do the programs and opportunities in Thunder Valley’s Regenerative Development provide job training in sustainable construction skills, and new home ownership opportunities, but also provide resources and training in growing healthy food. Pine Ridge Indian Reservation is a food desert and the high incidence of diabetes, and heart disease regionally are partly due to poor diet. Beginning in Phase 1, an aquaponics greenhouse and a hoophouse will be built and programmed to provide a healthy food source and training to residents and employees at Thunder Valley. In future phases two more are planned along with a small grocery store. Thunder Valley seeks to become a beacon of healthy behavior and resources for the vulnerable population they serve.

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Aging Infrastructure

Since the site is undeveloped, the proposed infrastructure at Thunder Valley is primarily based on Phase 1 in addition to proper planning of future phases.

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Reasonable Growth

Thunder Valley will develop a total of 21 units of single family housing in Phase 1 of the development at Thunder Valley. In order to achieve affordability , build community and increase the capacity of the local workforce Thunder Valley will deploying three different strategies in sweat equity and training models that will result between 15-30% cost savings for low income Native American families living in the development.

in the form of no-interest loans. SDHDA will take a mortgage position on the home site during construction and construction funds will be paid back once permanent financing is obtained through one of the following lending products: 502 direct, 502 guaranteed, 184 guaranteed, VA lending product, conventional mortgage or long term financing through SDHDA.

USDA 523 MUTUAL SELF-HELP PROGRAMThis program will have a total of two cohorts of six families over the two year Phase 1 period for a total of 12 units built in Phase 1 using this model. Thunder Valley CDC currently has a $288,000 pending Technical Assistance Grant from the USDA to start the first two cohorts and will reapply for the final two cohorts (for 12 units in Phase 2) when the Self-Help Program is up and running. This program will primarily be staffed by a Group Coordinator and Construction Trainer/ Supervisor with administration and planning support from the leadership team at Thunder Valley CDC. In the new master plan design there will be a total of 7 “culturally-based pocket sub-neighborhoods” throughout the development. The participants won’t only be building homes but neighborhoods and community with each other. The construction and permanent financing for the self-help houses will be coming primarily from the USDA 502 direct loan.

The above and following is an excerpt from the Thunder Valley Phase 1 Housing Plan (See attachment 3 for full plan.)

The three sweat equity programs being deployed at Thunder Valley include:

WORKFORCE DEVELOPMENT THROUGH SUSTAINABLE CONSTRUCTION PROGRAMThis program has capacity to provide on-the-job training for 10 participants every 10 months where they will build a house from start to finish. Each participant will develop individual education and success plans. They will receive a stipend of $600 every two weeks. Thunder Valley staff for this program includes a Program Manager, Construction Trainer and Education Coordinator. This program is being funded by a 5-year $2.5 million dollar grant from the Administration for Native Americans under the Sustainable Employment Economic Development Strategies (SEEDS) grant program. The program, will produce one house every 10 months and a total of two houses within the two year Phase 1 Housing Plan at Thunder Valley. These homes will have between 15-30% sweat equity that will be passed down to low-income families for the purchase of their homes. The construction funds for these homes will come from the South Dakota Housing Opportunity Fund (SDHOF) administered by the South Dakota Housing Development Authority

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FIGURE 6 : PHASE 1

FIGURE 7 : PHASE 2 FIGURE 8 : PHASE 3

Playground

Basketball Court

Bunkhouses

Community Building

Existing WorkforceTraining

Greenhouses

24’ wide road typ.(21) Single family homes typ.

Shared greenspace

Alleys and driveways typ.

Single family garden typ.

Existing NASHI House

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YOUTH BUILDThe Youth Build model will be focused on serving youth aged 16-24 who are currently unemployed and out of school. Through this program a cohort of 20-30 participants will be in the program for 10 months. The primary goals of this program is to build the skills and confidence of young people in the community. The by-product of this alternative education program will be a home built with equity in it that will be passed down to a low-income family for homeownership. The cohort will produce onehome every ten months. This program is funded by a U.S. Department of Labor YouthBuild grant for $1.1 million to operate the program for a 27 month period. 70% of all Youth Build Grants are re-funded by the Department of Labor after obtaining first-time funding. In 2014 Thunder Valley CDC was a finalist for a Youth Build grant and are working with Youth Build USA Inc. the national Technical Assistance provider for the program to increase our capacity and better position us for funding in 2015. If funded we would launch the program in September - October of 2015. The grant will pay for stipends, tools, equipment and staffing which includes: program manager, construction trainer 1, construction trainer 2, counselor, GED Tutor and case manager. Again, the result of this model is a subsidized house available for purchase. The equity in the homes, as a result of the program, will be passed down to a low income family for home ownership. The construction funds for materials to build the homes through this program will come from the South Dakota Housing Opportunity Fund (SDHOF) administered by the South Dakota Housing Development Authority in the form of

no-interest loans. SDHDA will take a mortgage position on the home site during construction. Construction funds will be paid back once permanent financing is obtained through one of the following lending products: 502 direct, 502 guaranteed, 184 guaranteed, VA lending product, conventional mortgage or long term financing through SDHDA. TVCDC is exploring the possibility that the YouthBuild Program could also be used to construct the shared community house in Phase 1 of the Development.

TIMELINE & PLAN FOR PHASE 1 YEARS 1-2

Year 1 – 2015• Water & sewer infrastructure built• Electrical infrastructure built • Roadways and parking lots built • A total of 21 single family lots fully developed • 6 self-help housing units built (1st cohort) • 1 workforce development house built, financed

and sold (1st cohort)• 3 commercially built housing units built

Total: 21 lots fully developed and 10 homes completed.

Year 2 - 2016• 6 self-help homes built (2nd cohort)• 1 workforce development house (2nd cohort) • 4 commercially built housing units built• 1 community house built using YouthBuild (1st

cohort)

Total: 21 single family homes and 1 community house built

Existing WorkforceTraining

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Thunder Valley CDC will be partnering with First National Bank out of Rapid City, South Dakota in our Federal Home Loan Bank (FHLB) Affordable Housing Program Application. First National Bank is a member Bank of the FHLB and will be the sponsoring bank partner on the application. In our Federal Home Loan Bank Application we will request $30,000 of subsidy per unit for 14 units in Phase 1 of the Thunder Valley development. Thunder Valley CDC will achieve a conditional commitment from the Oglala Sioux Lakota Housing Authority of $5,000 per unit for 14 units in the development. The Oglala Sioux Lakota Housing Authority will write the 14 unit subsidy into their NAHASDA Annual Housing Plan for 2015 and 2016. Having Tribal, NAHASDA dollars in the project makes the project and Thunder Valley CDC eligible for the 10 extra points for Native American/Tribal Communities with the FHLB Affordable Housing Program (AHP).

In addition to the NAHASDA and FHLB subsidy, Thunder Valley CDC will secure a $2,5000 downpayment assistance subsidy for 14 units from the South Dakota Housing Development Authority. Thunder Valley CDC will also coordinate with Lakota Funds and OST Partnership for Housing to secure Individual Development Accounts (IDA’S) for 14 home owners in Phase 1.

In addition to the above cash subsidy, the Self-Help built homes will also be eligible for HUD Self-Help Opportunity Program dollars. This program is a $15,000, 90% deferred loan for families who contribute to 100 hours of sweat equity into their homes. This means that for 12 units in Phase

1 there will be an additional $13,5000 of cash subsidy for the purchase of their home. Following is the breakdown of cash subsidy per type of homeownership program:

• Self-Help Program Built homes, 12 units, subsidy per unit $56,000.00

• Workforce Development Build Homes, 2 units, subsidy per unit $42,500.00

• Commercially Build Homes, 7 units, subsidy per unit $0

The estimated monthly Home Ownership Association Fee will be approximately $132.00 based on the O & M of the water, sewer, storm, and road infrastructure. It is possible that this fee could be reduced if OST Rural Water would agree to take on the operation and maintenane of the water system. In the near term, Thunder Valley CDC will take on debt acquired and will use revenue tied to the selling of the lots to service the debt. The initial plan is to use 306C Grant dollars for Water and Sewer, 1780 Grant dollars for Stormwater, and a two-year site development loan for roads and sidewalks. The planned strategy is to create a Sanitary District for the funding of future phases. In order to create this Sanitary District, three individuals who are registered to vote must live in the development. Remaining loan dollars will be rolled into the Sanitary District for long term financing.

While Phase 1 is under construction (2015-2016), a market study will be accomplished to include multi-family and commercial support structures in

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Phase 2. At this time application for tax credits will be made for Phase 2. Phase 2 (2017-2018) will include the expansion of Phase 1 infrastructure to accommodate the construction of 11 single family homes (6 Self Help, 1 Workforce, 4 commercially built), the central ring of mixed use buildings, the small grocery store, and northern townhome buildings. Phase 3 will include the final infrastructure expansion, the last townhomes on the southern side, mixed use buildings along the frontage road, and the school. (See Appendix D for labelled Full Buildout Plan)

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Alternatives Considered

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Water Supply

The system will need to be designed to meet a peak hourly flow of 60 gallons per minute during Phase I of the project. There are three main alternatives to evaluate for the water system to supply such demands. They consist of:• No Build• Utilizing the Oglala Sioux Rural Water Supply System –

Oglala Sioux Tribes Department of Water Maintenance and Conservation (OST Rural Water)

• Connecting to groundwater wells

After a description of the general design criteria, these alternatives can be seen in further detail below, and are only evaluated as they pertain to the first phase of the project. See Appendix A for supporting information.

GENERAL DESIGN CRITERIA The following sections and corresponding tables represent the projected flows used for the design of Phase I of the Thunder Valley Community. Phase I is comprised of three 1-bedroom, seven 2-bedroom, and eleven 3-bedroom single family residences; one bunkhouse; a workforce training center; and a greenhouse.

Design criteria used for the Thunder Valley Community water system are based on the following: City of Rapid City, South Dakota Infrastructure Design, 2012; Ten States Standards; Criteria for Design of Public Water Supply Facilities in South Dakota, SDDENR, 1979; Social/ Physical Impacts and Water Consumption Characteristics of South Dakota’s Rural Water Systems.

There are several factors that impact the determination of expected water demand. On page 27, Table 1 Projected Flow Factors, illustrates each of these.

Small populations tend to have high peaking factors compared to larger populations. A peaking factor of eight was assumed based on engineering judgment.

Water DemandWater demand during the Phase I of the project was determined using the expected population within the phase. The breakdown of units can be seen on page 27 Table 2: Phase I Water Demand. For water demand determination purposes, it was assumed that on average one-bedroom homes contain two residents, two-bedroom homes contain four residents, three-bedroom homes contain six residents, and the bunkhouse contains eight residents. A workforce training center with fifteen staff and thirty six participants and a greenhouse with three staff are also expected in Phase I. These commercial/industrial demands are taken into account along with the residential demand.

The expected population is multiplied by a daily per capita water demand of 100 gallons to find the average daily demand for the community. Average daily demands are based on a yearly average and don’t represent periods of low water use such as in winter or high water use such as hot days during the summer when more water is demanded. The high demand days are considered peak days, and the estimated demand for these days is determined by multiplying the average daily demand by a peak day peaking factor. Peak day demand is expected to be two and a half times

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TABLE 1 PROJECTED FLOW FACTORS

TABLE 2 PHASE 1 WATER DEMAND

28

greater than the average daily demand for Phase I. Just as water demand is not consistent throughout the seasons, it is not consistent throughout the day. Periods of high water demand typically occur in the morning and evening hours during the week when people are preparing for work and returning home. These instances are referred to as “peak hour” which are determined by multiplying the average day by a peak hour peaking factor and then converting to an hourly flow.

Using these assumptions, Phase I of the project is expected to require an average of 11,610 gallons per day, with a peak hour demand of 65 gallons per minute.

It is expected Phase I will not require fire flow. A community fire protection system is not financially practical for a small population. If fire flow is needed for any of the Phase I structures it will need to be addressed with a cistern and sprinkler system for the individual structure.

ALTERNATIVES SCREENEDNO BUILD ALTERNATIVEWith the “No Build” alternative, no construction would be completed for the Thunder Valley Community. Therefore the infrastructure will not be constructed, consequently the needed housing will also not be constructed and the current housing shortage will continue. This does not accomplish the objectives of the project and is therefore not a viable alternative.

UTILIZING THE OST RURAL WATER SYSTEM ALTERNATIVEDescriptionThis alternative includes constructing a Thunder Valley water system that would connect to the existing 8-inch water main running along BIA 27 that is owned and operated by OST Rural Water.

The maximum pressures set forth in 10 States Standards is 100 psi. The existing OST Rural Water system has a relatively high static pressure of approximately 120 psi near the proposed development. The source pressure would need to be reduced to acceptable pressures prior to delivery to the end user. Reducing pressures can be accomplished by installing pressure reducing

valve (PRV) at the master meter connection. OST Rural Water has indicated they would be able to supply the development with 125 gpm. This is more than the required peak hour demand of 60 gpm during Phase I, and leaves adequate flow as a buffer.

Though the OST Rural Water system will be capable of meeting the community’s water needs throughout the first phase, the flow will not be large enough to provide any fire protection. Thus, fire protection would be limited to water brought to the site via tankers or cistern.

MapA system layout was developed to maximize system looping at build out and minimize the length of pipe utilized. See page 29, Figure 9: Alternative 2 Utilizing the OST Rural Water System, which illustrates this preliminary layout for Phase I.

The minimum allowable size for water mains is 3 inches. The peak hour flow of 65 gpm results in a velocity of 2.9 feet per second (ft/sec). This is below the maximum acceptable velocity of 5 ft/sec. Therefore, 3 inch mains are expected to be adequate for Phase I.

Environmental ImpactsEnvironmental impacts would be minimal since the connection to the existing 8-inch OST Rural Water main would be located along the west side of BIA 27 in the existing row crop field. It has been determined that the existing development site does not have critical environmental habitat and construction of the development, specifically the water system, would have minimal impacts to the environment. Mitigation measures will be undertaken as identified in the Environmental Report.

Land RequirementsThere would be no additional land requirements to connect to the existing 8-inch OST water main. Additionally, the proposed water system would be located on land owned by the Thunder Valley Community Development and would not require the purchase of any additional land. Easements would be created for the existing 8-inch OST water main and the proposed water system allowing for maintenance of the facilities.

Potential Construction ProblemsConstruction issues regarding the installation of the proposed water system and connection to the existing 8-inch OST Rural Water main would

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FIGURE 9 ALTERNATIVE 2 UTILIZING THE OST RURAL WATER SYSTEM

3” Water Line

3” Water Line

Connect to existing 8” OST Water Line

30

likely be minimal. Groundwater and bedrock were not encountered during a previous geotechnical investigation boring that was taken to a depth of twenty feet.

Sustainability Considerationsi) Water and Energy Efficiency: The existing 8-inch rural water supply line that currently runs along BIA 27 to the east of the development site can provide a safe potable water supply of 125 gallons/minute to the development with no operating cost. This existing infrastructure provides affordable and proven access to clean water for new home owners and business owners in this development. This alternative also allows Thunder Valley the opportunity to create a sustainable funding stream to maintain their infrastructure through the future creation and management of a utility district.

ii) Green Infrastructure: This water supply alternative is not a green infrastructure opportunity, however, because of the supply limit being 125 gpm, it is important to make sure that the development is planning for water efficiency from the first day of operation in order to achieve its density goals at full build out. To prepare a more resilient community that anticipates less rainfall and more extreme weather events due to climate change, integrated water solutions are required to utilize every drop as a precious resource. This resilience planning is important particularly in vulnerable and rural populations.

Cost Estimate breakdown including O&MOn page 31, Table 3: Water System w/ Connection to Existing OST Rural Water Cost Estimate,

depicts the estimated cost of this alternative. The water system, while functioning on its own, requires routine operation and maintenance. It is anticipated that through an agreement with OST Rural Water, that they will provide system monitoring, inspections, and routine maintenance.

Advantages & DisadvantagesThe advantage of connecting the proposed water system to the existing 8-inch OST Rural Water main is that it will then be supplied by a larger regulated system. Experienced and certified staff can be contracted to operate and maintain the proposed system. Also, by connecting to the existing OST Rural Water main, adequate quality water would be provided and the resulting environmental impacts would be minimized. Environmental impacts would be minimized because the only construction necessary would be located in an existing farm field, an area that does not have critical environmental habitat.

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TABLE 3 WATER SYSTEM WITH CONNECTION TO EXISTING OST RURAL WATER COST ESTIMATE

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GROUNDWATER WELLS ALTERNATIVEDescriptionThis alternative proposes constructing a Thunder Valley water system which would obtain water through groundwater wells. A minimum of two wells would be required in order to provide redundancy for the system; however it is possible more than two wells would be required to supply the peak day demand of 60 gpm. While multiple wells are expected to be capable of meeting peak hour demands, they would not deliver adequate flow to provide any fire protection.

Assuming enough wells capable of producing the demand can be drilled, the proposed system would be constructed using three inch water mains.

In order to evaluate the potential for using groundwater at this site, wells logs acquired from the South Dakota Department of Environment and Natural Resources (SDDENR) website were examined for the wells in a radius of approximately three miles surrounding the site. Pertinent information from these wells can be found on page 34, Table 4: Well Data. Static water depths, overall well depth and pump test values were taken from well logs. The hydraulic formation information comes from United States Geological Survey (USGS) figure entitled Hydrogeology of the Pine Ridge Indian Reservation, South Dakota, Sheet 1 of 2, prepared in 1971.

The abbreviations for the hydrogeological formations are as follows:• Qfa – Flood-plain alluvium• Qta – Terrace alluvium (Qta is combined with Qfa in the table because the well locations on the well logs are not adequately detailed to differentiate between the two formations.)• Qwd – Windblown sand deposits• Ta – Arikaree Formation

Based on information presented in Table 4, it seems likely that groundwater would be reached at a depth less than 75 feet. The pump test data available for the wells within this formation are not very promising. The majority of available well capacities are less than 10 gpm. At 10 gpm per well, the development would require seven wells to provide peak day demands for Phase 1. It should be noted that more wells would be required if less than 10 gpm was determined to be the production rate. • (60 gpm) / (10 gpm per well) = 6 wells • Include additional well for redundancy

However, it is possible these wells were only required for livestock and did not need to produce more than 5-10 gpm. If this is the case, they may be capable of higher production. It should also be noted that each of these wells has a relatively shallow depth. It may be possible that because of the low flow required for livestock use, the wells were purposefully not drilled deep. Had the wells been drilled deeper into a different aquifer, more water may have been available. In addition to the depth of the wells, the diameters are relatively small with all but one ranging from 4 to 6 inches. Utilizing a larger diameter could potentially yield more water.

Through discussions with a local well driller, it was confirmed that obtaining more than about 5-10 gpm from a shallow well is unlikely. According to this well driller, a deeper well would be more likely to produce more water. It will be likely that the depth of the well will be close to 3,000 ft, pumping water from the Inyan Kara Formation. This will result in a significant increase in the capital cost with each well at 3,000 ft costing approximately $250,000 apiece. It is not guaranteed a well will produce adequate water even with drilling into the Inyan Kara Formation. For the purposes of the following cost estimate, it will be assumed that wells are drilled to a depth of approximately 3,000 feet with a yield of 50 gpm. Therefore, three wells will be required to meet peak hour water demand during the first phase of the project, including one for redundancy.

There is a great deal of uncertainty regarding the quantity or quality of groundwater available at the Thunder Valley site. If this alternative is chosen, two test wells should be drilled on opposite corners of the site. This should help develop a more accurate indication of the hydrogeological conditions of the proposed site. If test wells are drilled, pump tests should be performed to determine the- potential well capacities.

Samples should be taken from the test wells to determine the quality of water that can be expected. The following constituents should be tested along with any others that may be unique to the area as determined in consultation with the well drilling contractor:• All primary drinking water standards• Total dissolved solids (TDS)• Bac-T• Sodium• Calcium• Magnesium• Manganese• Iron

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It should be noted that this alternative will only be viable if water rights can be secured for any wells drilled at the site.

MapA system layout was developed to maximize system looping in the system at full build-out and minimize the length of pipe utilized. On page 34, Figure 10: Alternative 3, Ground Water Wells Water System illustrates this preliminary layout for Phase I.

Environmental ImpactsEnvironmental impacts would be limited since the new water system and groundwater wells would be constructed within the development which is currently a farm field and pasture. Compared to the other water alternatives, there is a slightly increased environmental risk to drilling wells. Although remote, there is a possibility of groundwater contamination with well drilling that is not associated with connecting to the rural water system. It has been determined that the existing development site does not have critical environmental habitat, and construction of the development and specifically the water system is expected to have minimal impacts to the environment. Mitigation measures will be undertaken as identified in the Environmental Report.

Land RequirementsIt is expected there would be no additional land requirements to drill the groundwater wells and construct the water system, as these would be located on land owned by the Thunder Valley Community Development. However, it should be noted that if adequate water cannot be obtained from wells drilled on the site, additional land may be required for additional wells and piping to connect to those wells. Easements would be created for the proposed water system within the development allowing for maintenance of the facilities.

Potential Construction ProblemsConstruction issues regarding the installation of the proposed water system and groundwater wells would likely be very minimal. Groundwater and bedrock were not encountered during a previous geotechnical investigation boring that was taken to a depth of 20 feet. It should be noted that the potential of not finding adequate water to supply the demand could present a construction problem.

Sustainability ConsiderationsGiven the high number of unknowns prior to drilling test wells, this alternative requires a great

deal of exploration and investment in order to understand its feasibility and safety of quantity and quality of water available. However, since this alternative is managed entirely on-site, Thunder Valley has the option to explore this alternative for supplemental potable water to the OST Rural Water line over time, or for a decentralized water supply in the event of an emergency. This exploration is aligned with Thunder Valley’s research agenda on Lakota health, welfare, and self-sufficiency.

Cost Estimate breakdown including O&MOn page 35, Table 5: Water system with Connection to Groundwater Wells Cost Estimate, depicts the estimated cost of utilizing a water system connected to groundwater wells. The water system, while functioning on its own, requires routine operation and maintenance. It is anticipated that through an agreement with OST Rural Water, that they will provide system monitoring, inspections, and routine maintenance. The increase of this alternative over other alternatives is that wells add mechanical equipment that requires more operational and maintenance costs such as; electricity for the well pumps, water quality monitoring, additional operator labor, and maintenance of mechanical equipment. Based on a 3,000 foot pumping head from the well at 10,800 gallons per day the electricity cost is estimated at $6,000 per year. A contract to monitor the wells and water quality is expected to cost $15,000 per year. Annual maintenance costs at 2% of capital costs assumes component replacement at 40 year intervals.

Advantages & DisadvantagesThe advantage of utilizing this alternative is that Thunder Valley Community Development would have rights to the water and would be able to control the rates charged for water usage.

The disadvantages of this alternative are that water quality and quantity is still unknown and additional construction would be required to drill the test wells. Poor water quality could necessitate constructing water treatment facilities, which can be expensive. Additionally, it is possible more wells would be required in addition to the two assumed in this cost estimate. This will result in a significant increase in the capital cost with each well at 3,000 ft costing approximately $250,000 apiece. This system may also call for additional staff than would be required to connect to OST Rural Water. Additional staff will cause the development to incur additional operation and maintenance costs.

34

TABLE 4 WELL DATA

FIGURE 10 ALTERNATIVE 3, GROUND WATER WELLS WATER SYSTEM

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TABLE 5 WATER SYSTEM CONNECTED TO GROUNDWATER WELLS COST ESTIMATE

36

Waste Water

There are numerous methods and technologies for treating wastewater; however, not all are feasible or applicable for this development. Therefore, the following six alternatives will be analyzed for viability. • No Build• Constructed Wetland Bioreactor System• Trickling Filter• Trickling Filter and Constructed Wetland Bioreactor Hybrid• Discharge into Existing Sharps Corner Lagoon• On-site Facultative/Aerated Lagoon System• Cluster Septic System with Drain Field or Mound Disposal

Each alternative will be discussed after a description of the general design criteria necessary to develop solutions for waste water treatment and disposal at the development. See Appendix B for supporting information.

GENERAL DESIGN CRITERIA Design criteria used for the Thunder Valley Community were developed from Ten States Standards - Recommended Standards for Wastewater Facilities; Recommended Design Criteria Manual Wastewater Collection and Treatment Facilities, SDDENR, 1991, and South Dakota Chapter 74:53:01 Individual And Small On-site Wastewater Systems.

Wastewater FlowThe Thunder Valley development is new and therefore lacks historic flow data. In the absence of historic data, flows are based on estimated occupancy of residential and commercial property. Table 6: Phase 1 Projected Wastewater Flows (page 37), depicts the anticipated wastewater flow generated from Phase 1 for all housing units, workforce training center, bunkhouse, and greenhouses.

As can be seen in Table 6, Phase 1 wastewater treatment/disposal will need to be designed to meet the average day flows of approximately 11,600 gallons. Applying a peaking factor of 4.2 (from the Ten State Standards) results in a peak hourly flow of 48,500 gallons per day.

Wastewater StrengthThe strength of the wastewater generated by the proposed development has been assumed to be medium strength,. These concentrations have been determined using Metcalf & Eddy’s Wastewater Engineering Treatment/Disposal/Reuse, domestic untreated wastewater concentrations. On page 37, Table 7: Projected Influent Wastewater Concentrations, shows the estimated concentrations of waste that will be generated by the development.

Treated Effluent QualityThe expected effluent requirements depend on the mode of disposal. For Phase 1, two methods of disposal will be considered: surface and subsurface. Surface disposal would involve discharging treated water into an intermittent stream bordering the south property boundary that flows into Porcupine Creek. Subsurface disposal would occur into the ground through a drain field or mound. At full build out, a third disposal method, reuse, can be evaluated. Anticipated discharge and wastewater reuse guidelines have been provided in Table 8: Projected Effluent Quality Requirements.(page 37).

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37Table X: Projected Influent Wastewater Concentrations

TABLE 6 PROJECTED WASTEWATER FLOWS

TABLE 7 PROJECTED INFLUENT WASTEWATER CONCENTRATIONS

TABLE 8 PROJECTED EFFLUENT QUALITY REQUIREMENTS

38

ALTERNATIVES SCREENEDNO BUILD With the “No Build” alternative, no infrastructure or new housing would be constructed. Because limited housing is the reason for the project, this option will not be considered.

CONSTRUCTED WETLAND BIOREACTOR (CWB) A CWB system treats wastewater by using a tank or settling basin as a form of primary treatment before discharging to a man-made wetland area. The primary treatment is required to remove any trash, suspended solids, as well as any oil/grease materials within the wastewater prior to entering the CWB.

The effluent is treated using naturally occurring biological reactions through aerobic and anaerobic processes in the wetland. The CWB typically consists of approximately three feet of coarse gravel with a top layer of fine gravel. A shallow berm as well as an impervious liner are used to aid in the elimination of surface runoff and groundwater contamination. The influent wastewater is maintained approximately 2.5 to 3.5-inches below the top of the gravel ensuring the top layer stays dry, odor is not produced, and insects cannot breed. This also helps to eliminate the danger for human contact with the wastewater during the treatment process.

The layer of coarse gravel within the CWB provides a solid surface for microorganisms to grow and stabilize without obstructing the effluent flow. Local vegetation, typically those known to thrive in wetland conditions, is planted within the layers of gravel providing aesthetic appeal as well as promoting the secondary treatment process. The root system of the planted vegetation offers additional surface area for the microorganisms to attach and grow to greater numbers. As a result, with more microorganisms, the effluent is treated faster. The root systems also carry oxygen and emit a wide variety of molecules, known as plant exudates, which stimulate the microbial system further increasing the treatment of the effluent. CWB systems alone cannot treat ammonia to levels required for year round surface discharge. To meet discharge limits year round, substantial modification including a heated area and recirculation of the influent would be required. Therefore a standalone CWB system will not be evaluated in detail.

TRICKLING FILTER A trickling filter system consists of a primary tank, aerated equalization tank, and dosed filter media. The primary tank allows solids to settle and separates oils and grease. The water is then moved to an equalization tank where it is aerated and dosed over a media. Microorganisms grow on the media and treat the wastewater. This type of system is capable of handling a wide range of flows and can be easily expanded. In addition, a relatively small foot print would be required for it to be capable of meeting the surface water discharge effluent requirements. For these reasons the trickling filter alternative will be considered in more detail.

TRICKLING FILTER AND CONSTRUCTED WETLAND BIOREACTOR HYBRID This option involves combining a CWB system with a trickling filer. This could potentially decrease the size of the trickling filter system and the required CWB size by combining treatment. For these reasons this alternative will be considered in more detail.

DISCHARGING INTO THE EXISTING SHARPS CORNER LAGOONWithin a ¼ mile of the site there is a two cell, total retention lagoon system currently receiving wastewater from residential and commercial structures near Sharps Corner. Aerial photographs of the site indicate large seasonal fluctuations in water level and vegetation growth below the high water mark. Based on these two factors and knowing the lagoon was constructed in 1973 it is reasonable to assume that the lagoon is exceeding the exfiltration limit. Any future use of these cells will require substantial rehabilitation. To accommodate the wastewater flow from Thunder Valley, the lagoon system would require a new primary cell. In an attempt to stay within the existing IHS property boundaries, the total retention lagoon system must be converted to a discharging facultative lagoon system. The nearest discharge point is Porcupine Creek. Ammonia limits exist along the section of Porcupine Creek adjacent to the lagoon system. The ammonia limit would require aeration in the cells or the addition of ammonia reduction system. To meet ammonia limits, it is likely that additional land would be required to accommodate all treatment infrastructure. There is available land around the lagoon that could potentially be acquired to expand the facility, however; land owners in the area are reluctant to sell. Even if land were available, Thunder Valley does not own the Sharps

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Corner Lagoon and would have limited authority in the operation and maintenance of the system. The engineering team investigated the flow and cost to rehabilitate and expand the lagoon to accommodate Phase 1 (see Appendix B, page 149). The preliminary cost in this analysis is conservative, however it does not account for meeting ammonia limits for discharge required by the EPA, which translates to an additional treatment step and therefore an even higher cost than this estimate reflects. In comparison to other treatment alternatives, the cost for the lagoon rehabilitation is not of modest cost. Furthermore, the Tribe has indicated that this lagoon is not one of their priority rehabilitation projects in the near term (see letter in Appendix B, page 151). For these reasons, the alternative of expanding the lagoon at Sharps Corner will not be developed further.

ON-SITE FACULTATIVE/AERATED LAGOON SYSTEMSConstructing a facultative or aerated lagoon system on the other side of the highway from the Thunder Valley development and on the existing 34 acre development was considered. The owners of the land east of the Thunder Valley development were offered 3 times the fair market value of the land, but were unwilling to sell. There is not enough space on the existing site to construct a lagoon, provide appropriate separation from permanent residences, and meet development goals. An aerated lagoon system would reduce the total footprint compared to a facultative lagoon system. However, the footprint is still substantial. Therefore, constructing a facultative or aerated lagoon system for the Thunder Valley Development will not be considered in detail.

CLUSTER SEPTIC SYSTEM WITH DRAIN FIELD OR MOUND DISPOSAL Individual septic and drain field systems were considered as a treatment and disposal option. However, The SDDENR require a minimum lot size of 20,000 square feet for an individual septic tank and drain field. The proposed development has lot sizes less than 20,000 square feet. Therefore, a cluster septic and drain field or mound system was investigated to avoid the area restriction. According to the NRCS web soil survey the soil on site has an average percolation rate of 55 minutes per inch (mins/in). This is an average value and could be higher or lower depending on where the drain field is placed. The minimum percolation rate permitted by South Dakota is 60 minutes per inch for a traditional drain field. Soils with percolation rates slower than 60 minutes per inch

require a mound system for disposal. Soil tests would be required where the drain fields would be constructed to determine if this is a viable option.

It is estimated that a total of 2.4 acres (including 100% replacement area) would be required to treat and dispose of wastewater from Phase 1 with four separate septic tank and drain field systems (traditional). If percolations rates are between 60 and 120 mins/in a total of 2.4 acres would be required (mound system). At full build-out, the estimated land requirement for septic tanks and drain field is 20 to 50 acres (including replacement areas), depending on disposal method. Clearly at full build out, a septic system is not a viable option due to the amount of land required. However, due to the small scale of Phase 1 and the ammonia limit for surface discharge, this option will be considered in detail.

40

DETAILED ALTERNATIVESCLUSTER SEPTIC SYSTEM WITH DRAIN FIELD OR MOUND DISPOSAL Description This alternative proposes constructing 4 cluster septic and drain field or mound systems (see Figure 11, page 41). Primary treatment is provided in the septic tank. Effluent from the septic tank flows into a dosing chamber. The option exists for combining the septic tank and dosing chamber into one tank (Figure 12, page 41). From the dosing chamber, effluent is pumped to the disposal area through pressurized pipe. The SDDENR requires pressure dosing systems if the total length of absorption lines exceed 750 or the total absorption area is greater than 1,200 square feet. All 4 cluster septic systems exceed both criteria. From the dosing chamber, wastewater is pumped to the drain field or mound for disposal.

The proposed location of the drain fields that will dispose of effluent from septic tanks treating wastewater from the residential homes are on the hillside to the west of the homes. The undisturbed slopes within the area identified for the drain fields range from 10% to 20%. To meet slope restrictions, drain fields will be moved to slopes nor greater than 12% (hillside or other location). To ensure that effluent does not reach the surface, a geotechnical investigation will be conducted before the final design is completed. The geotechnical investigation will identify any bedrock or soil formations (i.e., clay or sand layer) under the proposed drain fields that might facility movement of wastewater to the surface. Barring any unforeseen problems with bedrock near the surface or problematic soils, wastewater should not daylight due to the slope of the hillside.

MapOn page 41, see Figure 13 for proposed layout of system.

Environmental Impacts It has been determined that the existing development site does not have critical environmental habitat. Therefore, construction of the development, specifically the septic systems, would have minimal impacts to the environment. Power requirements would be extremely low.

Land Requirements There would be no additional land acquisition required to construct the cluster septic systems since it would be located on land owned by the Thunder Valley Community Development. For

Phase 1, all 4 systems would occupy approximately 2.4 acres using drain fields or mounds (includes replacement areas). However, at full build the amount of area needed for drain fields or mounds would make this method prohibitive.

Construction Problems Construction issues regarding the installation of the proposed cluster septic systems would likely be very minimal. Neither groundwater nor bedrock were encountered during previous geotechnical investigation boring that was taken to a depth of twenty feet. The only issue with this option is locating appropriate soil conditions and percolation rates to allow the construction of cluster septic systems.

Sustainability Considerations Water and Energy Efficiency: The cluster septic system has very low energy demand compared to mechanical treatment methods. The wastewater will likely flow by gravity to the septic tanks and dosing chambers. Pumps located in the dosing tanks would distribute water to the disposal areas, which are sited so that they can remain in place throughout all phases of development and utilize their full life span. This system is nearly maintenance free. Sludge and trash build up in the septic tanks would need periodic removal. Also, this solution is affordable for the Phase 1 homeowners which helps to create an economically sustainable community from the beginning, while planning for an increasingly efficient one. When it is time to replace the tanks, or upgrade the system, the 21 homes can easily be tied into a trickling filter type of system described in the next alternative.

Cost Estimates On page 42, Table 9: Cluster Septic Treatment System With Drain Field Disposal Cost Estimate Phase 1, depicts the estimated cost of constructing and operating 4 cluster septic systems with drain field disposal. Costs are only estimates. More accurate costs would require a complete design.

If percolation rates do not allow the use of a traditional drain field, then a mound disposal system is an option for disposal. On page 42, Table 10: Cluster Septic Treatment System With Mound Disposal Cost Estimate Phase 1, depicts the estimated cost of constructing and operating four cluster septic systems with mound disposal. Costs are only estimates. More accurate costs would require a complete design.

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FIGURE 11 CLUSTER SEPTIC SYSTEM DIAGRAM FIGURE 12 COMBINATION SEPTIC TANK AND DOSING CHAMBER

FIGURE 13 PROPOSED LAYOUT OF CLUSTER SEPTIC SYSTEM

2894

N 85°12'17" E

354.10'

2885

2890

2895

2900

2905

2910

2915

2920

2925

2890

2895

2880

2880

2880

2886

2890

2892

2895

2885

2887

2889

28902892

28902892

2889

2890

2935

2885

2890

2910

2915

2920

2895

2905

2920

2921

2900

2890

2890

2897

2880

S 0

0°11

'13"

W26

34.2

6'

PROPOSED DRAINFIELD (TYP.)

PROPOSED DRAINFIELDREPLACEMENT AREA (TYP.)

-MANHOLE-SEPTIC TANK-DOSING CHAMBER

GRAVITY MAIN

GRAVITY MAIN

GRAVITY MAIN

SEPTIC TANK

SEPTIC TANK

SEPTIC TANK

SEPTIC TANK

DOSING CHAMBER

DOSING CHAMBER

DOSING CHAMBER

FORCE MAIN

FORCE MAIN

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TABLE 9 CLUSTER SEPTIC TREATMENT WITH DRAINFIELD COST ESTIMATE PHASE 1

TABLE 10 CLUSTER SEPTIC TREATMENT WITH MOUND DISPOSAL COST ESTIMATE PHASE 1

TABLE 11 O&M COSTS FOR CLUSTER SEPTIC TREATMENT COST ESTIMATE PHASE 1

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Advantages A cluster septic system is the lowest cost wastewater treatment alternative considered for the Phase 1. The cluster septic system is relatively easy to operate and maintain. The system will not require a certified operator as would be required for a mechanical system. Environmental impacts would be minimal since the proposed system is located in an area that does not have critical environmental habitat. Subsurface discharge avoids having to meet ammonia limits of Porcupine Creek. The system is energy efficient since it only uses a small dosing pump.

Disadvantages At full build out, the amount of land required to continue this method of treatment/disposal would render drain fields impractical.

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TRICKLING FILTERDescriptionThis alternative proposes constructing a Trickling Filter treatment system. Primary treatment is provided in underground tanks. The Trickling Filter system utilizes a recirculating media filter to produce high quality effluent capable of meeting the surface water discharge requirements. The system would also withstand the extreme temperature variations that can occur between seasons in South Dakota. (See system diagram page 45, Figure 14.) To meet discharge limits in Phase 1, the system would consist of a primary tank, aerated equalization tank, trickling filter, and dosing and recirculation pumps, chemical treatment system (maintain pH levels), and a UV disinfection unit. The quality of treated effluent should meet or exceed the surface water quality limits in Table 8 (page 38). The treated effluent can be discharged into the nearby drainage that flows to Porcupine Creek. Discharge into the unnamed tributary would provide the watershed with additional flow and would ultimately provide some recharge to groundwater aquifers. In order for surface discharge to occur, a National Pollutant Discharge Elimination System (NPDES) surface discharge permit would be required.

MapOn page 45, see Figure 15 for proposed layout of system.

Environmental ImpactsIt has been determined that the existing development site does not have critical environmental habitat. Therefore, construction of the development, specifically a trickling filter system, would have minimal impacts to the environment.

Also, power requirements will be low and the treated wastewater would be very high quality, and discharging to Porcupine Creek would not be detrimental to its water quality.

Land RequirementsThere would be no additional land requirements to construct the Trickling Filter System since it would be located on land owned by the Thunder Valley Community Development. The system itself will take up less than 1,500 sf for Phase 1. At full build out less than half an acre will be required for the treatment system.

Construction ProblemsConstruction issues regarding the installation of the proposed Trickling Filter treatment system would likely be very minimal. Groundwater was not encountered during previous geotechnical

investigation boring that was taken to a depth of twenty feet and bedrock was also not encountered. Sustainability ConsiderationsWater and Energy Efficiency: The trickling filter alternative has a very low energy demand compared to other mechanical treatment methods. The wastewater flows by gravity to the trickling filter and once it reaches the primary tanks on site, small pumps and fans are used to circulate water through the system. These mechanical elements may be solar powered with a battery backup. This adaptable linear system is easy to expand in the central location as the development grows in each phase and the packaged units are stable and straightforward to maintain. This system also provides points toward LEED certification, if Thunder Valley opts to pursue that system of certification. Trickling filters are an efficient, affordable, simple, plug-and-play approach to achieving high quality effluent. In future phases, Thunder Valley would have the option to build upon this system to clean and disinfect the effluent to even higher standards for reuse either for irrigation or possibly for graywater uses in commercial and institutional buildings on site.

Other: This option has the smallest footprint of all alternative studied, thereby leaving more land open to the higher social and economic purposes of this development. This treatment alternative also creates an educational opportunity to train an on-site operator to maintain the system and educate all ages on the water cycle of their community.

Cost EstimatesThe table on page 46, Table 12: Trickling Filter Treatment Facility Cost Estimate Phase 1, depicts the estimated cost of utilizing such a facility. Costs are only estimates. More accurate costs would require a complete design.

AdvantagesThe advantage of constructing the Trickling Filter treatment system is it would provide a long term, quality system for the development. Environmental impacts would be minimal since the proposed system is located in an area that does not have critical environmental habitat and discharge would meet the required limits. The system is energy efficient and has the smallest foot print of the alternatives analyzed. This system is easily expandable for future phases, so its components never become redundant.

DisadvantagesThis alternative requires a trained operator to sample the wastewater and maintain the mechanical parts of the system and the first cost is also slightly higher than other alternatives.

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Trickling Filters with Integrated Clarifiers

(2 in series)

Recycled Flow and Settled Sludge

Wastewaterfrom Community

(Phase 1)

SurfaceDischarge

UV Disinfection Unit

UV

8,000 gallon Primary Treatment Tank

baffled @ 2/3 volume

2,500 gallon Aerated Flow Equalization Tank

with Submersible Aerator

Alkalinity Addition System

Alkalinity

Ventilation Fan

TRICKLING FILTER

FIGURE 14 TRICKLING FILTER SYSTEM DIAGRAM

FIGURE 15 PLAN OF TRICKLING FILTER SYSTEM

46

TABLE 12 TRICKLING FILTER FACILITY COST ESTIMATE PHASE 1

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48

TRICKLING FILTER AND WETLAND BIOREACTOR HYBRIDDescriptionThis alternative proposes constructing a Trickling Filter treatment system followed by a CWB systems. The wastewater would flow from the trickling filter into a CWB system to receive final treatment. The two systems would be designed together to meet the permit requirements. Due to the low ammonia limit the majority of the treatment would be performed by the trickling filter and the CWB system would function as a final polishing step. (See system diagram on page 49, Figure 16)

This hybrid system would have a larger foot print than the stand alone trickling filter system but still maintain an above ground plant component to the wastewater treatment system. The hybrid system could be easily expanded to meet future growth just like the trickling filter.

MapOn page 49, see Figure 17 for proposed layout of system.

Environmental ImpactsIt has been determined that the existing development site does not have critical environmental habitat. Therefore, construction of the development, specifically the hybrid trickling filter CWB treatment system, would have minimal impacts to the environment.

Furthermore, the treated wastewater discharged into the unnamed tributary would have minimal impacts on the environment because the effluent produced would be of such high quality.

Land RequirementsThere would be no additional land requirements to construct the hybrid treatment system since it would be located on land owned by the Thunder Valley Community Development. The land required for this treatment option is dependent on how big the end wetland is sized for. Phase 1 land requirements could easily be 15,000 sf or more. For the full build out the system would likely require at least an acre.

Construction ProblemsConstruction issues regarding the installation of the proposed hybrid treatment system would likely be very minimal. Neither groundwater nor bedrock were encountered during the geotechnical investigation. Borings were taken to a depth of twenty feet.

Sustainability ConsiderationsWater and Energy Efficiency: Like the trickling filters option, this is a low energy waste water treatment alternative that is adaptable and expandable to achieve reuseable quality of effluent in future phases of development. Since it requires more land to execute and additional tending and maintenance of plant materials, it is not as efficient as the trickling filter option, however the water quality is potentially higher and educational opportunities are greater.

Green Infrastructure: In Phase 1 the constructed wetland bioreactor acts as the final polishing stage of the waste water system. Cold climate solutions have been designed and executed successfully, especially privately-owned and operated systems, such as this would be, because private systems tend to be better maintained (see attachment 4 for articles and case studies). The habitat and ecosystem that develops as a by product of the Constructed Wetland Bioreactors could have a significant environmental benefit to the land and community. The educational opportunities expand from simply waste water treatment, to biological processes that can be observed and cultivated season to season. Educating youth and adults in green infrastructure solutions could have far-reaching economic and health impacts on Pine Ridge Indian Reservation and beyond. Not only does cultivating the success of highly operational green infrastructure solutions take an adaptive, and experimental mindset, but also a mindset that Mother Earth deserves our very best, and that every living thing is connected to one another, which is aligned with Lakota tradition and spirituality. Inculcating these principles in daily life is a goal of Thunder Valley Development.

Cost EstimatesThe table on page 50, Table 13: Trickling Filter and CWB Treatment Facility Cost Estimate Phase 1 provides a cost estimate for the hybrid system. For cost estimating purposes, the price for the trickling filter was kept the same with an additional sum for the wetland construction because most of the treatment will be done in the trickling filters, however in final design there may be some cost benefit from the two systems being together in an integrated system.

AdvantagesThe hybrid system offers the appeal of providing a natural amenity, habitat, biodiversity and education opportunity to provide the highest quality waste water.

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49

TRICKLING FILTER

CONSTRUCTED WETLANDBIOREACTOR

FIGURE 16 HYBRID SYSTEM DIAGRAM

FIGURE 17 PLAN OF HYBRID SYSTEM

Trickling Filters with Integrated Clarifiers

(2 in series)

Recycled Flow and Settled Sludge

Wastewaterfrom Community

(Phase 1)

SurfaceDischarge

UV Disinfection Unit

UV

8,000 gallon Primary Treatment Tank

baffled @ 2/3 volume

2,500 gallon Aerated Flow Equalization Tank

with Submersible Aerator

Alkalinity Addition System

Alkalinity

Ventilation Fan

Trickling Filters with Integrated Clarifiers

(2 in series)

Recycled Flow and Settled Sludge

Wastewaterfrom Community

(Phase 1)

SurfaceDischarge

UV Disinfection Unit

UV

8,000 gallon Primary Treatment Tank

baffled @ 2/3 volume

2,500 gallon Aerated Flow Equalization Tank

with Submersible Aerator

Alkalinity Addition System

Alkalinity

Ventilation Fan

Constructed Wetland Bioreactor

50

TABLE 13 TRICKLING FILTER AND CWB FACILITY COST ESTIMATE PHASE 1

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51

DisadvantagesThis system does present the problem of increased complexity. An operator is required that has a working understanding of each system. While this would not be impossible, it does require a more skillful, knowledgeable operator. The foot print of this option is larger than just using the trickling filter system. This could adversely impact future development by reducing the available land for development. First cost is also a disadvantage.

52

Stormwater

There are three alternatives for the storm drain system. They consist of:• No Build• Utilize curb, gutter, inlets, storm drains and culverts• Utilize curb, gutter, inlets, and storm drains

These alternatives can be seen in further detail below. See Appendix C for supporting information.

NO BUILDWith the “No Build” alternative, no construction would be completed for the Thunder Valley Community. Therefore the infrastructure will not be constructed, consequently the needed housing will also not be constructed and the current housing shortage will continue.

CURB, GUTTER, INLETS, STORM DRAINS AND CULVERTSa) DescriptionThis alternative proposes to construct curb and gutter along the western roadway that would convey runoff north to proposed inlets and storm drain. The storm drain would then discharge into a swale that would be constructed at minimal slopes and contain native plantings. The eastern north/south roadway would utilize roadside swales rather than curb and gutter, where the swales would convey flow north. The flow within the swale would be conveyed under the alleys and northern most roadway by culverts that would safely convey the 100-year storm. The swale will provide water quality treatment by using physical properties of plants, soil, and microbes to remove suspended solids, hydrocarbons, and other contaminants.

Thunder Valley Phase 1 was delineated into nine sub-basins that were analyzed based on proposed imperviousness, estimated flow paths and acreage. Flows from the sub-basins were then routed using the Rational Method to determine street flow capacity, inlet, storm drain and culvert sizing. The analysis determined that sub-basins A-1, A-2 and A-1A would flow north and would not exceed street flow capacity. At the northern portion of

sub-basin A-1 a sump is proposed where inlets will capture runoff which would then be conveyed east via 18-inch storm drain to sub-basin A-4. Sub-basins A-3, A-4 and A-4A will flow east and north along the proposed roadway swales where runoff will be conveyed by proposed culverts. The flows from basins A-1 through A-4 will then combine with A-6 near the northern portion of the site. The combined flows will then be conveyed by a proposed 24-inch culvert then flows into a swale that will discharge into the existing BIA Highway 27 roadside ditch.

Preliminary analysis of existing conditions determined the anticipated peak flows. Developed flows were calculated and shown on page 53 in Table 14: Developed Flows. See Appendix C, page 149 for basin plan.

b) Design Criteria Design criteria used for the Thunder Valley Community are City of Rapid City, South Dakota Infrastructure Design, 2012.

c) MapOn page 53, Figure 18 illustrates the proposed system.

d) Environmental ImpactsIt has been determined that the existing development site does not have a critical environmental habitat. Construction of the development, specifically the storm drain system, would have minimal impacts to the environment. The curb, gutter, inlets, storm drain, culverts and swales would safely convey runoff and also provide

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TABLE 14 DEVELOPED FLOWS

FIGURE 18 PLAN OF ALTERNATE 2, CURB, GUTTER, INLETS, STORM DRAINS, AND CULVERTS

* See Appendix C, page 149 for basin plan

54

water quality treatment prior to discharging into BIA Highway 27 roadway ditch. Mitigation measures would be undertaken as identified in the Environmental Report.

e) Land RequirementsThere are no additional land requirements to construct the storm drain system since it would be located on land owned by the Thunder Valley Community Development. Easements would be created for the proposed system to allow for maintenance.

f) Potential Construction ProblemsConstruction issues regarding the installation of the proposed storm drain system and bio-swale would likely be very minimal. Groundwater was not encountered during previous geotechnical investigations. Borings were taken to a depth of twenty feet and no bedrock was encountered.

g) Sustainability ConsiderationsGreen Infrastructure: This alternative uses native planted swales along the western and eastern roads to remove many of the contaminants and sediment from runoff. In this area of the site where gravity-fed drainage occurs, the swales move stormwater away from the structures and off of pathways for the safety and walkability of community members. This solution provides an aesthetic amenity to the community, as well as habitat for native species of plants and animals. This alternative also provides educational and workforce opportunities for community members to learn about the cultivation and proliferation of native species and implementation of green infrastructure solutions region-wide.

Other: This alternative is also planned for future phases to capture the rainwater on the north and east in storage tanks for rainwater reuse.

h) Cost Estimates On page 55, Table 15: Curb, Gutter, Inlets, Storm Drain and Culverts depicts the estimated cost of utilizing such a facility.

i) Advantages & DisadvantagesThe advantage of constructing the proposed storm drainage system with curb, gutter, inlets, storm drain and culverts is that it would provide a long-term quality system for the development. Additionally, constructing the system is the most cost effective alternative for construction. It provides the water quality treatment by utilizing swales which also reduces the amount of storm drain piping required. Environmental impacts are minimal since the proposed system would be located in an area that does not have critical environmental habitat.

CURB, GUTTERS, INLETS, AND STORM DRAINSa) DescriptionThis alternative proposes constructing curb and gutter adjacent to all proposed roadways that would convey runoff to inlets and storm drain that would then discharge into the existing BIA Highway 27 roadside swale.

Thunder Valley Phase 1 was delineated into nine sub-basins that were analyzed based on proposed imperviousness, estimated flow paths and acreage. Flows from the sub-basins were then routed using the Rational Method to determine street flow capacity, inlet and storm drain sizing. The analysis determined that sub-basins A-1, A-2 and A-1A would flow north and would not exceed street flow capacity. At the northern portion of sub-basin A-1 a sump is proposed where inlets will capture runoff which would then be conveyed east via 18-inch storm drain to sub-basin A-4. Sub-basins A-3, A-4 and A-4A will flow east and north along the proposed roadway curb and gutter to a sump location where inlets will capture the flow which will then be combined with the western storm drain that then flows east to BIA 27 via a 24-inch diameter storm drain. The flows from basins A-6 and A-6A near the northern portion of the site will be captured by inlets and storm drain that will also convey flows northeast to BIA 27.

Preliminary analysis of existing conditions determined the anticipated peak flows. Developed flows were calculated and shown on page 53 in Table 13: Developed Flows.

b) Design CriteriaDesign criteria used for the Thunder Valley Community are City of Rapid City, South Dakota Infrastructure Design, 2012.

c) MapThe figure on page 56, Figure 19, illustrates the proposed system.

d) Environmental ImpactsIt has been determined that the existing development site does not have critical environmental habitat. Construction of the development, specifically the storm drain system, would have minimal impacts to the environment. Mitigation measures would be undertaken as identified in the Environmental Report.

e) Land RequirementsThere would be no additional land requirements to construct the storm drain system and since it would be located on land owned by the Thunder Valley Community Development. Easements would be created for the proposed system to allow for maintenance.

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55

TABLE 15 CURB, GUTTER, INLETS, STORM DRAINS, AND CULVERTS COST ESTIMATE

56 FIGURE 19 PLAN OF ALTERNATE 3, CURB, GUTTER, INLETS, AND STORM DRAINS

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57

f) Potential Construction ProblemsConstruction issues regarding the installation of the proposed curb, gutter and storm drain system would likely be very minimal. Groundwater was not encountered during previous geotechnical investigations. Borings were taken to a depth of twenty feet and no bedrock was encountered.

g) Sustainability ConsiderationsThis is a high quality long term solution to stormwater conveyance that is also planned for future phases to capture the rainwater on the north and east in storage tanks for rainwater reuse.

h) Cost EstimatesSee page 58, Table 16 for Curb, Gutter, Inlets, and Storm Drain Cost Estimate.

i) Advantages & DisadvantagesThe advantage of constructing the storm drain system with concrete curb, gutter, inlets and storm drains is it would provide a long-term quality system to the development. Environmental impacts would be minimal since the proposed system is located in an area that does not have critical environmental habitat.

Disadvantages would be the increased cost of constructing the curb, gutter and additional storm drain compared to the other constructed alternative.

58

TABLE 16 CURB, GUTTER, INLETS, AND STORM DRAINS COST ESTIMATE

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59

60

Roadways

There are four alternatives for the roadway system. They consist of:• No Build• Asphalt Roadways• Concrete Roadways• Gravel Roadways• Chip Seal (Blotter) Roadways

These alternatives can be seen in further detail below.

GENERAL INTENT OF ROAD CONFIGURATIONThe loop road and alleys in Phase 1 are designed to provide safe and durable access to the single family home tiospayes while maximizing community space and encouraging pedestrian activity in the development. Parking areas are primarily located on the low-speed alleys, and the homes are organized around central shared community spaces that open to the east, as is traditional in Lakota culture.

The loop road also provides an accessible width and route for emergency vehicles to assist the residents and businesses of Thunder Valley Regenerative Development.

NO BUILDWith the “No Build” alternative, no construction would be completed for the Thunder Valley Community. Therefore the infrastructure will not be constructed, consequently the needed housing will also not be constructed and the current housing shortage will continue.

ASPHALT ROADWAYSa) DescriptionThis alternative suggests the construction of asphalt roadways throughout the development. Asphalt concrete (AC) pavements are considered to be high-type pavements intended to serve intermediate to high traffic volumes or heavy wheel loads. Conventional AC pavements are layered systems, typically consisting of an asphalt concrete surface placed on one or more layers of bound or unbound granular materials, which in turn are placed on the existing subgrade soil. The

roadways would be 24 feet wide with 5-inch thick asphalt pavement underlain by a 6-inch aggregate base course.

b) Design CriteriaDesign criteria used for the Thunder Valley Community are City of Rapid City, South Dakota Infrastructure Design, 2012 and SDDOT Local Roads Surfacing Criteria – SD 2002-10-F (published in 2004). The surfacing criteria developed a methodology for determining life-cycle cost comparisons of various surfacing options.

c) MapOn page 61, Figure 20 illustrates the extent of the proposed system.

d) Environmental ImpactsIt has been determined that the existing development site does not have critical environmental habitat. Construction of the development, specifically the roadway system, would have minimal impacts to the environment. Mitigation measures would be undertaken as identified in the Environmental Report.

e) Land RequirementsThere would be no additional land requirements to construct the roadways since it would be located on land owned by the Thunder Valley Community Development. Right of ways would be created for the proposed roadways to allow for maintenance.

f) Potential Construction ProblemsConstruction issues regarding the installation

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61FIGURE 20 ROADWAY SYSTEMS EXTENT

Proposed Roadway Surfacing

62

of the proposed roadways would likely be very minimal. Groundwater was not encountered during previous geotechnical investigations. Borings were taken to a depth of twenty feet and no bedrock was encountered.

g) Sustainability ConsiderationsAsphalt has a relatively long life and can be made of locally found recycled road materials, and recycled in the future, which means that its initial carbon footprint is lower than that of concrete, however the lifespan of concrete is longer.. Asphalt roads can be constructed and in use in a much shorter timeframe than concrete roadways, which can be a deciding factor in the productivity of the road and phased development. Asphalt roadways are a lower cost in the short term, allowing for a lower cost burden to the first residents. Asphalt would be a significant upgrade compared to the gravel roads in most nearby housing developments and seen as a major quality of life improvement.

h) Cost Estimates On page 63, Table 17: Asphalt Roadways Cost Estimate, depicts the estimated cost of utilizing such a facility.

i) Advantages & DisadvantagesThe advantage of constructing the asphalt roadways is it would provide a long term quality system to the development. Additionally, constructing the asphalt roadways rather than gravel roadways would reduce airborne dust particulate and ultimately provide a stable roadway. Environmental impacts could be minimal since the proposed roadways would be located in an area that does not have critical environmental habitat and runoff can be directed to native plantings that help to clean the water of toxins prior to discharge off the site. Typically asphalt contains recycled materials.

Disadvantages are that asphalt is a non-renewable, petroleum based product. Walking on asphalt can track heavy metals and petroleum products into households where they can cause adverse health impacts in pets and small children.

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TABLE 17 ASPHALT ROADWAYS COST ESTIMATE

64

CONCRETE ROADWAYSa) Description This alternative proposes to construct Portland cement concrete roadways throughout the development. Portland cement concrete (PCC) pavements are referred to as rigid pavements. ThePCC is typically placed on an aggregate (gravel) base layer. The roadways would be 24 feet wide with a 7-inch thick concrete pavement underlain by 4-inch aggregate base course. Additionally, rebar dowels would be constructed at each horizontal joint similar to SDDOT criteria. (High flyash and slag could be substituted for Portland and achieve a lower carbon footprint with the same performance properties.) b) Design CriteriaDesign criteria used for the Thunder Valley Community are City of Rapid City, South Dakota Infrastructure Design, 2012 and SDDOT Local Roads Surfacing Criteria – SD 2002-10-F (published in 2004). The surfacing criteria developed a methodology for determining life-cycle cost comparisons of various surfacing options.

c) MapOn page 61, Figure 20 illustrates the extent of the proposed system.

d) Environmental Impacts It has been determined that the existing development site does not have critical environmental habitat. Construction of the development, specifically the roadway system, would have minimal impacts to the environment. Mitigation measures would be undertaken as identified in the Environmental Report.

e) Land RequirementsThere would be no additional land requirements to construct the roadways since it would be located on land owned by the Thunder Valley Community Development. Right of ways would be created for the proposed roadways to allow for maintenance.

f) Potential Construction ProblemsConstruction issues regarding the installation of the proposed roadways would likely be very minimal. Groundwater was not encountered during previous geotechnical investigations. Borings were taken to a depth of twenty feet and no bedrock was encountered.

g) Sustainability ConsiderationsConcrete is one of the most consistent and

utilized building material throughout any project. Concrete is a durable and resilient material that contributes to sustainability. Some factors that make-up concrete can contribute to not only the performance but also the environmental footprint. Specifically, the factors available could be cement replacement with flyash and slag and recycled aggregate polished back into the original aggregate (so it uses less cement), recycled water, site stabilization, and locally produced materials. A concrete road eliminates airborn dust, it has a less toxic profile and does not off-gas or track heavy metals on shoes. Concrete also produces less heat island effect than darker materials, such as asphalt or chip seal, which makes a better pedestrian experience.

h) Cost Estimates Table 18: Concrete Roadways Cost Estimate, on page 65 depicts the estimated cost of utilizing such a facility.

i) Advantages & DisadvantagesThe advantage of constructing the concrete roadways is it would provide a long-term quality system, require minimal maintenance and has an approximate life of 50 years. Additionally, constructing the concrete roadways, rather than gravel roadways, would reduce airborne dust particulate and ultimately provide a healthier lifestyle. Environmental impacts would be minimal since the proposed roadways would be located in an area that does not have critical environmental habitat and concrete roadways have less heat island effect compared to asphalt.

Disadvantages would be the additional up front costs to construct the concrete roadways.

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TABLE 18 CONCRETE ROADWAYS COST ESTIMATE

66

GRAVEL ROADWAYSa) DescriptionThis alternative proposes constructing gravel roadways throughout the development. Gravel roads are referred to as low-type surfaces because they usually serve low traffic volumes. This surface type provides the lowest level of service. The basic structure of gravel roads consists of a gravel layer of adequate thickness and quality overlying the subgrade. Structurally, gravel-surfaced roads function as flexible pavements. Structural capacity is achieved by spreading the load over the weaker underlying soil (the subgrade). The roadways would be 24 feet wide, with a 6-inch thickness of gravel.

b) Design CriteriaDesign criteria used for the Thunder Valley Community are City of Rapid City, South Dakota Infrastructure Design, 2012 and SDDOT Local Roads Surfacing Criteria – SD 2002-10-F (published in 2004). The surfacing criteria developed a methodology for determining life-cycle cost comparisons of various surfacing options.

c) Map On page 61 Figure 20 illustrates the extent of the proposed system.

d) Environmental ImpactsIt has been determined that the existing development site does not have critical environmental habitat. Construction of the development, specifically the roadway system, would have minimal impacts to the environment. Mitigation measures would be undertaken as identified in the Environmental Report.

e) Land RequirementsThere would be no additional land requirements to construct the roadways since it would be located on land owned by the Thunder Valley Community Development. Right of ways would be created for the proposed roadways to allow for maintenance.

f) Potential Construction ProblemsConstruction issues regarding the installation of the proposed roadways would likely be very minimal. Groundwater was not encountered during previous geotechnical investigations. Borings were taken to a depth of twenty feet and no bedrock was encountered.

g) Sustainability ConsiderationsGravel roadways are status quo for residential

development in the region and provide a quick and inexpensive roadway, though they are fraught with maintenance issues in this harsh climate. They do not provide a friendly pedestrian surface because of their dustiness, and would not provide a sustainable solution for the Thunder Valley Development to set itself apart as a healthy and walkable community.

h) Cost Estimates On page 67, Table 19: Gravel Roadways Cost Estimate, depicts the estimated cost of utilizing such a facility.

i) Advantages & DisadvantagesThe advantage of constructing the gravel roadways is it would provide roads at minimal cost to the development.

Disadvantages primarily involve the weekly maintenance of the roadway surface as well as the environmental impacts of the road dust. Road dust is made of coarse particles that can aggravate heart or lung-related conditions such as asthma when inhaled through the nose and mouth. Although coarse particles do not go as deep into the lungs as fine particles, they can still have adverse impacts to susceptible individuals. Sensitive individuals or people with respiratory conditions can reduce their health risks by staying indoors or away from dirt roads when there are dry conditions with significant traffic or wind. Additional environmental impacts due to gravel roadways are typically water quality degradation after storm events.

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TABLE 19 GRAVEL ROADWAYS COST ESTIMATE

68

CHIP SEAL OR BLOTTER ROADWAYSa) Description This alternative proposes constructing blotter-surfaced roadways throughout the development. A blotter-surfaced road is considered an intermediate-type road. A blotter road consists of a surface treatment placed on a granular base. The surface treatment consists of a uniform application of asphalt cement to a road surface, followed immediately by a layer of aggregate chips. The surface treatment may be as thin as 6 mm (0.25 in) or as thick as 25 mm (1 in), depending on the size of the aggregate chips and the number of surface treatment applications. On lightly traveled roads, blotters provide a relatively long-term, inexpensive pavement that does not dust, corrugate (washboard), or lose surface materials from the abrasive action of vehicle tires. However, on roads carrying heavier volumes of traffic (especially trucks), the blotter pavement provides a comparatively short service life. For this project two applications are recommended.

b) Design CriteriaDesign criteria used for the Thunder Valley Community are City of Rapid City, South Dakota Infrastructure Design, 2012 and SDDOT Local Roads Surfacing Criteria – SD 2002-10-F (published in 2004). The surfacing criteria developed a methodology for determining life-cycle cost comparisons of various surfacing options.

c) Map On page 61, Figure 20 illustrates the extent of the proposed system.

d) Environmental ImpactsIt has been determined that the existing development site does not have critical environmental habitat. Construction of the development, specifically the roadway system, would have minimal impacts to the environment. Mitigation measures would be undertaken as identified in the Environmental Report.

e) Land RequirementsThere would be no additional land requirements to construct the roadways since it would be located on land owned by the Thunder Valley Community Development. Right of ways would be created for the proposed roadways to allow for maintenance.

f) Potential Construction ProblemsConstruction issues regarding the installation of the proposed roadways would likely be very

minimal. Groundwater was not encountered during previous geotechnical investigations. Borings were taken to a depth of twenty feet and no bedrock was encountered.

g) Sustainability ConsiderationsBlotter roadways provide a stable solution for the first 10 years of low speed roads of this development. In order to keep a low carbon footprint, they may use recycled local materials, and at the end of their life may be recycled as base course for a concrete or perviously paved road upgrade, if the development deems appropriate at that time. This affordable roadway is also more pedestrian-friendly than a gravel road, but less so than a concrete or pervious paving system due to the dark color (heat absorption), petroleum based sealant which can lead to tracking heavy metals indoors, and runoff water quality concerns.

h) Cost Estimates On page 69, Table 20: Blotter Roadways Cost Estimate, depicts the estimated cost of utilizing such a facility.

i) Advantages & DisadvantagesThe advantage of constructing the blotter roadways is it would provide roads at minimal cost to the development, however the disadvantages are blotter roadways typically have a short life span of approximately 10 years and high yearly maintenance costs.

Environmental impacts could be minimal since the proposed roadways would be located in an area that does not have critical environmental habitat and runoff can be directed to native plantings that help to clean the water of toxins prior to discharge off the site.

Disadvantages are that the sealant is a non-renewable, petroleum based product. Walking on this material can track heavy metals and petroleum products into households where they can cause adverse health impacts in pets and small children.

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TABLE 20 BLOTTER ROADWAYS COST ESTIMATE

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Selection of an Alternative

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Water Supply

LIFE CYCLE COST ANALYSISA comparison of alternatives can be seen on page 73, Table 21: Water System Alternatives. It should be noted, however, the uncertain nature of the water quality available from wells is not taken into account in the cost estimate below. Should water quality not meet drinking water standards, a water treatment facility will need to be constructed, which will significantly increase the total cost of the project.

Based on the values presented in the above table, coupled with the uncertain nature of groundwater quality, the recommended alternative is to utilize the OST Rural Water System (Alternative II). This alternative is not only the most cost efficient, but minimizes the future risk of significant unforeseen costs associated with water treatment and poor well performance.

It should be noted that the above analysis and cost estimates does not take into account for future development and/or phases. The current phase does not account for fire flow. Fire protection could be provided on an individual structure basis using tankers or cisterns.

This PER does not address the additional phases which are planned for the development. This is at the request of the owner in association with funding requirements for the project. In typical engineering practice the full build-out development of the project would be accounted for in the initial phase of the design process. It is our professional opinion that not incorporating full build-out into the design of the first phase will result in increased cost to the project overall.

NON-MONETARY FACTORSThe water alternatives screened in this study can also be compared in a variety of non-monetary ways. The alternatives will be compared based on the following criteria:

• Footprint – How much area is required for the system?

• System Complexity – What level of operator training is required?

• Expandability – Can the process be easily expanded to accommodate future growth?

Each alternative is compared below within the framework of these criteria.

Footprint Connecting to the OST Rural Water System has the smallest footprint of the alternatives analyzed since less piping is required and well locations are not needed.

System Complexity Connecting to the OST Rural Water System is the least complex water system since treatment will not be required due to the water being supplied by a regulated source, additionally, the OST Rural Water System has more than adequate pressure reducing the need for additional pumping. Conversely, the well water option would likely require treatment, pumping and constant monitoring by an operator. Expandability The OST Rural Water alternative has additional expandability potential, however a larger

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TABLE 21 WATER SYSTEM ALTERNATIVES

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main within the development or an additional connection to the rural water main is likely based on the limited capacity of the Phase 1 3-inch diameter line. The well water alternative would require additional wells to meet any future needs along with expansion of treatment.

Comparison and Ranking of AlternativesUtilizing the monetary and non-monetary information presented above, a comparative summary evaluation and ranking of alternative combinations is presented in Table 2. For each of the criteria discussed above, all alternatives were assigned a ranking score from 1 to 5, with 5 being the most favorable and 1 being least favorable. The ranking factors were then multiplied by the relative weight of importance assigned to each evaluation criteria. The weighted rank scores were then summed, resulting in a weighted rank total score, the greatest score indicating the highest ranking. Under this ranking method, the highest possible score is 85 points. The weighting of each criterion, in descending order, was as follows:

• Cost Effectiveness - 5• Footprint - 3• System Complexity - 4• Expandability - 5

The weighting of the criteria has a substantial effect on the final alternative ranking. The weighting of the criteria is inherently open to differences of opinion. The weighting documented above and used in this analysis is suggested as a starting point, based on the relative importance of these factors as measured by other communities.

The developer should carefully consider these criteria and determine if they, in fact, reflect the consensus viewpoint.

Discussion and RecommendationsOn page 75, Table 22 presents a comparison of the alternatives based on the criterion discussed above. Connecting to the OST Rural Water System is the highest ranked alternative evaluated.

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TABLE 22 WATER SYSTEM ALTERNATIVES COMPARATIVE SUMMARY EVALUATION

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Waste Water

LIFE CYCLE COST ANALYSISThe table on page 77, Table 23, lists the treatment alternatives.

Based on values presented in the above table, the Cluster Septic system is the recommended alternative based on the lifecycle cost analysis.

NON-MONETARY FACTORSThe wastewater treatment alternatives screened in this study can also be compared in a variety of non-monetary ways. The alternatives will be compared based on the following criteria:

• Water Reuse – Is the treatment system capable of being modified to allow for graywater reuse in buildings or green space irrigation?

• Footprint – How much area is required for the system?

• System Complexity – What level of operator training is required?

• Expandability – Can the process be easily expanded to accommodate future growth?

Each treatment alternative is compared below within the framework of these criteria.

Water Reuse:The trickling filter and hybrid systems evaluated are capable of being modified to meet the most stringent water reuse regulations. The trickling filter and hybrid systems can easily meet the E. coli limit with UV disinfection and filters can be installed at the end of the system to meet strict turbidity requirements.

FootprintThe standalone trickling filter has the smallest footprint of the alternatives analyzed with an estimated area of 1,500 sf. The cluster septic systems and hybrid system would require substantially more area. The hybrid system could require between 6,000 to 7,000 sf and the cluster septic system would need a bit more than an acre, possibly more.

System ComplexityA cluster septic system is one of the least complex wastewater treatment systems available. Wastewater would flow by gravity to the septic tanks and dosing chambers. A relatively small pump in each dosing chamber would send wastewater to the disposal fields. The mechanical packaged treatment plants are designed for simplistic operation, but they have many more moving parts and require much more supervision and knowledge to operate. The mechanical systems will require an operator with general knowledge of wastewater processes and pump maintenance. There will be two pumps to maintain for the trickling filter system and 3 pumps requiring maintenance for the hybrid system. The two mechanical alternatives will likely require the same certification level of wastewater operators, but the hybrid system will require an operator to understand two very different treatment processes.

ExpandabilityThe cluster septic system has limited expandability while both mechanical alternatives can be expanded to meet the future design population.

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TABLE 23 WASTEWATER SYSTEM LIFE CYCLE COST ANALYSIS

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Additional units can be added to the process for the trickling filter and additional wetland area can be added after the first phase of construction is complete.

COMPARISON AND RANKING OF ALTERNATIVESUtilizing the monetary and non-monetary information presented above, a comparative summary evaluation and ranking of alternative combinations is presented in Table 24. For each of the criteria discussed above, all alternatives were assigned a ranking score from 1 to 5, with 5 being the most favorable and 1 being least favorable. The ranking factors were then multiplied by the relative weight of importance assigned to each evaluation criteria. The weighted rank scores were then summed, resulting in a weighted rank total score, the greatest score indicating the highest ranking. Under this ranking method, the highest possible score is 90 points. The weighting of each criterion, in descending order, was as follows:

• Cost Effectiveness - 5• Water Reuse - 1• Footprint - 3• System Complexity - 4• Expandability - 5

The weighting of the criteria has a substantial effect on the final alternative ranking. In this case, foot print has 3 times the weight (importance) of water reuse. The weighting of the criteria is inherently open to differences of opinion. The weighting documented above and used in this analysis is suggested as a starting point, based on the relative importance of these factors as

measured by other communities. The developer should carefully consider these criteria and determine if they, in fact, reflect the consensus viewpoint.

DISCUSSION AND RECOMMENDATIONSOn page 79, Table 24 presents a comparison of the treatment and disposal alternatives based on the criterion discussed above. The trickling filter is the highest ranked alternative evaluated. The trickling filter has the lowest footprint and highest expandability potential. However its cost effectiveness is extremely low. The final weighted score is close with the trickling filter system the highest total only by 2 points over the cluster septic system. The cluster septic system is recommended based on the cost effectiveness of the system and affordability for Phase 1 homeowners.

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TABLE 24 WASTEWATER SYSTEM ALTERNATIVES COMPARATIVE SUMMARY EVALUATION

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Stormwater

LIFE CYCLE COST ANALYSISThe table on page 81, Table 25, lists the stormwater alternatives.

Based on values presented in this table, the recommended alternative for the stormwater system is Alternative 2: Curb, Gutter, Inlets, Storm Drain and Culverts. This alternative is the most cost effective solution over the 20-year planning period, has the lowest yearly O&M and provides the best water quality treatment of the runoff by utilizing swales within the development. The swales will provide water quality treatment by using physical properties of plants, soil, and microbes to remove suspended solids, hydrocarbons, and other contaminants.

NON-MONETARY FACTORSThe stormwater alternatives screened in this study can also be compared in a variety of non-monetary ways. The alternatives will be compared based on the following criteria:

• Footprint – How much area is required for the system?

• System Complexity – What level of operator training is required?

• Expandability – Can the process be easily expanded to accommodate future growth?

• Environmental - What are the water quality components?

Each alternative is compared below within the framework of these criteria.

FootprintUtilizing Alternative 2, Curb, Gutter, Inlets, Storm Drain and Culverts has the smallest footprint of the alternatives analyzed since uses less piping and utilizes grass swales to convey flows. Alternative 3 requires more piping and inlets to safely convey flows.

System ComplexityBoth alternatives offer systems that are not complex and will not require constant monitoring. However, Alternative 3 will require slightly more maintenance since it has more inlets and overall lineal feet of piping. Expandability Both alternatives offer limited expandability as the storm drain systems are designed to convey flows being generated from contributing basins.

Environmental Alternative 2 offers the most environmental friendly option since it utilizes grass swales to convey stormwater. The grass swales will provide water quality treatment by using physical properties of plants, soil, and microbes to remove suspended solids, hydrocarbons, and other contaminants. Alternative 3 offers limited environmental benefit since it will convey flows via storm drain piping directly to Highway BIA 27 roadway ditch.

COMPARISON AND RANKING OF ALTERNATIVESUtilizing the monetary and non-monetary information presented above, a comparative summary evaluation and ranking of alternative

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TABLE 25 STORMWATER SYSTEM ALTERNATIVES LIFE CYCLE COST ANALYSIS

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combinations is presented in Table 26. For each of the criteria discussed above, all alternatives were assigned a ranking score from 1 to 5, with 5 being the most favorable and 1 being least favorable. The ranking factors were then multiplied by the relative weight of importance assigned to each evaluation criteria. The weighted rank scores were then summed, resulting in a weighted rank total score, the greatest score indicating the highest ranking. Under this ranking method, the highest possible score is 100 points. The weighting of each criterion, in descending order, was as follows:

• Cost Effectiveness - 5• Footprint - 3• System Complexity - 4• Expandability – 5• Environmental - 3

The weighting of the criteria has a substantial effect on the final alternative ranking. The weighting of the criteria is inherently open to differences of opinion. The weighting documented above and used in this analysis is suggested as a starting point, based on the relative importance of these factors as measured by other communities. The developer should carefully consider these criteria and determine if they, in fact, reflect the consensus viewpoint.

DISCUSSION AND RECOMMENDATIONSOn page 83, Table 26 presents a comparison of the alternatives based on the criterion discussed above. Connecting to the OST Rural Water System is the highest ranked alternative evaluated.

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TABLE 26 STORMWATER SYSTEM ALTERNATIVES COMPARATIVE SUMMARY EVALUATION

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Roadways

LIFE CYCLE COST ANALYSISOn page 85, Table 27, illustrates the roadway alternatives.

Based on values presented in the above table, the recommended alternative for the roadway system is Alternative 5: Blotter Roadways. This alternative is similar in long term cost to gravel, however it will provide a healthier lifestyle due to the reduction in air borne particulates generated from gravel. Additionally, the blotter roadways provide a low initial construction cost compared to the other alternatives.

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TABLE 27 ROADWAY SYSTEM ALTERNATIVES LIFE CYCLE COST ANALYSIS

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Proposed Project

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Preliminary Project Design

WATER SUPPLYIt is recommended that the Thunder Valley Regenerative Community utilize the OST Rural Water System. By utilizing the existing and larger Rural Water System the overall cost of constructing, operations and maintenance of the proposed Thunder Valley Development water system are much less.

Quality and quantityThe recommend water alternative is to connect to the larger regional OST Water System that provides quality treated water, operations and maintenance of the rural water system. OST Rural Water has indicated to Thunder Valley Development that they can allocate 125 gpm of water with an approximate operating pressure of 120 psi (see Appendix A).

TreatmentSince the recommend water alternative is to connect to the larger regional OST Water System treatment will not be necessary.

Pumping StationsThe OST Rural Water System has an approximate operating pressure of 120 psi near the Thunder Valley Development, therefore by connecting to the Rural Water system, the development does not need to provide additional pumping for the proposed system.

Distribution layoutThis alternative includes constructing a Thunder Valley water system that would connect to the existing 8-inch water main running along BIA 27 that is owned and operated by OST Rural Water. The proposed system would consist of 3-inch diameter water mains that can safely carry the peak hour flow of 60 gpm with a velocity of 2.7 feet per second (ft/sec). This is below the maximum acceptable velocity of 5 ft/sec.

A system layout was developed to maximize system looping at build out and minimize the length of pipe utilized, (See Figure 21, page 89)however the 3-inch mains are not able to provide fire flows and future fire hydrants and larger mains will be necessary at certain locations.

WASTEWATERIt is recommended that the Thunder Valley Regenerative Community construct a cluster septic system to treat wastewater generated by the development.

A cluster septic system provides the most cost efficient wastewater treatment for phase 1. Operating and maintenance costs are significantly less than the other alternatives evaluated. The intent is to place individual septic systems near phase 1 infrastructure. Ideally, the drain field or mound for each tiospaye would be constructed immediately to the west at the base of the hillside. This would allow the continued functionality of the systems during implementation of future phases. The septic tank and drain field or mound treating water from the work force training center and greenhouse would be situated near these structures.

If percolations rates are less than 60 mins/in, effluent from the septic tanks will be disposed via traditional drain fields. If percolation rates are between 60 and 120 mins/in, a mound system will be used to dispose of effluent. The treatment system is designed to treat a daily average of 11,600 gallons. This treatment method is proven to operate efficiently in cold weather climates.

Collection SystemThe wastewater from each house in a tiospaye, greenhouse, bunkhouse, and work force training center will flow by gravity through 4” service lines to 8-inch sewer mains that connect to one of four septic tanks.

TreatmentPrimary treatment will occur in the septic tanks. Solids will settle and oil and grease will be separated. Any trash entering the septic tank will be trapped. A filter attached to the exit pipe will prevent solids and debris from flowing to the dosing tank. All septic tanks will be sized based on regulatory guidelines.

Pumping StationsEffluent from the septic tanks will flow to the dosing tanks. A pump in the dosing tank will

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89FIGURE 21 WATER SUPPLY LAYOUT

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periodically distribute wastewater to the disposal area through small diameter pressurized pipe. Wastewater delivered to the disposal area will then receive secondary treatment.

StorageThe septic tanks and dosing tanks will provide wastewater treatment and storage.

STORMWATERIt is recommended that the Thunder Valley Regenerative Community implement the Curb, Gutter, Inlets, Storm Drain and Culverts alternative (Alternative 2). On page 55, Table 14 depicts the estimated cost of utilizing such a facility.

Collection system layoutThis alternative proposes to construct curb and gutter along the western roadway that would convey runoff north to proposed inlets and storm drain. The storm drain would then discharge into a swale that would be constructed at minimal slopes and contain native plantings. The eastern north/south roadway would utilize roadside swales rather than curb and gutter, where the swales would convey flow north. (see Figure 22, page 91)The flow within the swale would conveyed under the alleys and northern most roadway by culverts that would safely convey the 100-year storm. The swale will provide water quality treatment by using physical properties of plants, soil, and microbes to remove suspended solids, hydrocarbons, and other contaminants.

Pumping StationsThe recommended storm drain alternative will convey runoff utilizing gravity flow, therefore pumping is not necessary. By utilizing gravity flow equipment, energy, operations and maintenance costs are greatly reduced. Additionally, the use of gravity flow reduces the possibility of infrastructure malfunction and possible flooding of property.

Green InfrastructureThis alternative uses native planted swales along the western and eastern roads to remove many of the contaminants and sediment from runoff. In this area of the site where gravity-fed drainage occurs, the swales move stormwater away from the structures and off of pathways for the safety and walkability of community members. This solution provides an aesthetic amenity to the community, as well as habitat for native species of plants and animals. This alternative also provides educational and workforce opportunities for community

members to learn about the cultivation and proliferation of native species and implementation of green infrastructure solutions region-wide.

ROADWAYSIt is recommended that the Thunder Valley Regenerative Community implement the Chip and Seal or Blotter Roadways alternative.

Distribution layoutThis alternative is to construct 24 feet wide blotter roadways throughout the development. The blotter road will consist of an asphalt surface treatment placed on 6-inch thick granular base. (See Figure 23, page 91)

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FIGURE 22 STORMWATER SYSTEM LAYOUT

FIGURE 23 ROADWAYS LAYOUT

Proposed Roadway Surfacing

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Project Schedule

Acquisition is not shown in the project schedule below, because all infrastructure improvements recommended will occur on land currently owned by Thunder Valley CDC.

1. PER Submittal, February 6, 20152. Anticipated PER approval, March 6, 20153. Begin detailed survey and geotechnical

analysis, week of March 94. Anticipated funding approval, April 3, 20165. Consultants to begin Construction Documents,

week of April 66. Permit set of drawings (50% set) issued with

the following applications, May 1, 2015 • Water Service, OST Rural Water• Wastewater discharge notice, EPA• Underground Injection Control permit, EPA• Stormwater discharge, EPA• Highway Access, OST Transportation

Department7. 100% set of Construction Documents, May 29,

20158. Once permits received, plat lots, and meet with

County Commissioner for approval (meets first Friday of month, June 5th)

9. Advertisement for bids, June 8, 201510. Loan closing, July 13, 201511. Contract award and notice to proceed, July 31,

201512. Initiation of construction, August 10, 2015

Order of work:• Site grading• Underground utilities• Fine grading• Stake roads• Curb and gutter• Gravel base• Road surfacing

13. Substantial completion, October 23, 201514. Final completion, November 6, 201515. Initiation of operation, November 9, 2015

See graphic schedule on page 93, Figure 24

Home construction must be carefully coordinated within the infrastructure timeline. The sustainable construction workforce development program has outlined the following schedule for home construction in 2015.

1. Grading and compaction, July 27, 2015 - 1 week2. Form setting, slab and backfill - 2 weeks3. Wall and roof framing & sheathing - 2.5 weeks4. Exterior door and window installation - 1 week5. Exterior finish system - 1.5 weeks6. Interior framing and rough-in - 2 weeks7. Drywall and floor installation - 2 weeks8. Plumbing and electrical finish work - 1 week9. Interior doors, cabinetry, & carpentry - 2 weeks10. Exterior decks and clean up - 1 week

See graphic schedule on page 93, Figure 25

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FIGURE 24 GRAPHIC PROJECT SCHEDULE

FIGURE 25 GRAPHIC HOME CONSTRUCTION SCHEDULE

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94

Permit Requirements

Permits anticipated to construct the proposed Thunder Valley Development are shown in Table 28, page 94

Water Service PermitThe proposed water system will be served by connecting to the existing 8-inch Oglala Sioux Tribe Rural Water (OSTRW) main along the eastern portion of the site. The OSTRW indicated they can serve the facility and existing pressure in the main is approximately 120 psi, requiring a pressure reducer at the proposed buildings. An OSTRW water service permit will be required, see Appendix A. The water system and services will be constructed by the development contractor to OSTRW specification.

Wastewater Discharge PermitThere are no public or private collection or treatment systems nearby the proposed development where connection to the system is viable. Therefore, wastewater generated from the development will be treated onsite using a cluster septic system. The cluster septic system will likely require an EPA NPDES and Underground Injection Control permits, see Appendix C. The proposed onsite wastewater collection and treatment facility consists of a sewer collection pipe, septic tanks, dosing tanks, distribution valve boxes, and subsurface disposal areas that will be owned and maintained by the development.

Stormwater Discharge PermitThe area to be disturbed by construction of the proposed improvements is approximately 12-acres, consequently an EPA NPDES Construction General Permit Notice of Intent will required 14-days in advance of any disturbance. The permit will include a Stormwater Pollution Prevention Plan (SWPPP), which will detail how sediment, erosion controls and other best management practices will be implemented on the construction site. See Appendix B for permit application.

Highway Access PermitThe proposed development will connect to the existing BIA Highway 27 along the eastern portion of the site. The highway is owned and operated by the Oglala Sioux Tribe Transportation Department, which indicated they will require a traffic study that will analyze existing traffic versus future after the development is constructed. Additionally, the study will recommend any improvements needed along the highway such as turning lanes, reduction in speed, etc.

TABLE 28 PERMITS

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95

Sustainability Considerations

WATER SUPPLYWater and Energy EfficiencyThe existing 8-inch rural water supply line that currently runs along BIA 27 to the east of the development site can provide a safe potable water supply of 125 gallons/minute to the development with no operating cost. This existing infrastructure provides affordable and proven access to clean water for new home owners and business owners in this development. This alternative also allows Thunder Valley the opportunity to create a sustainable funding stream to maintain their infrastructure through the future creation and management of a utility district.

Green InfrastructureThis water supply alternative is not a green infrastructure opportunity, however, because of the supply limit being 125 gpm, it is important to make sure that the development is planning for water efficiency from the first day of operation in order to achieve its density goals at full build out. To prepare a more resilient community that anticipates less rainfall and more extreme weather events due to climate change, integrated water solutions are required to utilize every drop as a precious resource. This resilience planning is important particularly in vulnerable and rural populations.

WASTEWATERWater and Energy EfficiencyThe cluster septic system has very low-energy demand compared to mechanical treatment methods. The wastewater will likely flow by gravity to the septic tanks and dosing chambers. Pumps located in the dosing tanks would distribute water to the disposal areas, which are sited so that they can remain in place throughout all phases of development and utilize their full life span. This system is nearly maintenance free. Sludge and trash build up in the septic tanks would need periodic removal. Also, this solution is affordable for the Phase 1 homeowners which helps to create an economically sustainable community from the beginning, while planning for an increasingly efficient one. When it is time to replace the tanks, or upgrade the system, the 21 homes can easily be tied into a trickling filter type of system, or some

other small-footprint environmentally friendly system in the future.

STORMWATERGreen InfrastructureThis alternative uses native planted swales along the western and eastern roads to remove many of the contaminants and sediment from runoff. In this area of the site where gravity-fed drainage occurs, the swales move stormwater away from the structures and off of pathways for the safety and walkability of community members. This solution provides an aesthetic amenity to the community, as well as habitat for native species of plants and animals. This alternative also provides educational and workforce opportunities for community members to learn about the cultivation and proliferation of native species and implementation of green infrastructure solutions region-wide.

OtherThis alternative is also planned for future phases to capture the rainwater on the north and east in storage tanks for rainwater reuse.

ROADSBlotter roadways provide a stable solution for the first 10 years of low speed roads of this development. In order to keep a low carbon footprint, they may use recycled local materials, and at the end of their life may be recycled as base course for a concrete or perviously paved road upgrade, if the development deems appropriate at that time. This affordable roadway is also more pedestrian-friendly than a gravel road.

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Total Project Cost Estimate

The total project cost to construct sustainable water, wastewater, storm drain and roadway infrastructure is below. Also included below are non-construction costs such as engineering, staking, contingencies, legal and administration by the development.

TVCDC is applying for water supply and wastewater system financing through the USDA RD 306C program, stormwater financing through the 1780 program, and roads and electrical financing through the Rural Development Community Facilities programs (site electrical = $50,000).

The water supply and wastewater system (total cost $576,165) would have a loan interest rate of 3% with a term of 40 years. The roads and electrical (total cost $488,661) would have a loan interest rate of 3.75% with a term of 20 years.

The revenue tied to the selling of the lots will service debt. See Housing Plan, attachment 3, for complete description of financing and debt repayment.

SYSTEM OPERATION AND MAINTENANCEOnce construction of the proposed Thunder Valley Community water, wastewater, storm drain and roadways are complete, property owners of the Thunder Valley Community will be charged a fee to live within the planned community similar to a Home Owner’s Association fee. The fee will be used to operate and maintain the proposed systems.

Thunder Valley will complete a maintenance/operations agreement with OST Rural Water or a third party contractor to maintain the water supply system. OST Rural Water staff is certified and best equipped to maintain and monitor the proposed improvements. Since the site will be newly constructed there should be little to no water loss within the system. If the Bureau of Reclamation allows OST Rural Water to take over the potable water system for this development through the creation of a water utility district, then OST Rural Water will take on all associated operation and maintenance costs of water supply at that time.

CONSTRUCTION COSTS $237,360

NON-CONSTRUCTION COSTS $102,065

$339,425

CONSTRUCTION COSTS $178,000

NON-CONSTRUCTION COSTS $58,740

$236,740

CONSTRUCTION COSTS $350,497

NON-CONSTRUCTION COSTS $115,665

$466,162

CONSTRUCTION COSTS $329,820

NON-CONSTRUCTION COSTS $108,841

$438,661

CONSTRUCTION COST SUBTOTAL $1,095,677

NON-CONSTRUCTION COST SUBTOTAL $385,311

$1,480,988

$64,391

PROJECT TOTAL

TOTAL

STORMWATER

TOTAL

ROADS

TOTAL

TOTAL LOT COST (23)

PROJECT COSTS

WATER

TOTAL

WASTEWATER

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Annual Operating Budget

INCOMEIncome will be generated by implementing a monthly fee to the property owners that will fund operations and maintenance of the recommended alternatives for water, wastewater, stormwater and roads. The recommended alternative for each component takes into account the burden that will be placed on the individual property owner and recommends components that are sustainable, modest in cost and provide low operations and maintenance cost.

ANNUAL O&M

Please see the following pages for more detailed breakdown of Operation and Maintainance costs and Short Lived Asset costs for each category.

SYSTEM ITEM DESCRIPTION QUANTITY UNIT UNIT PRICE TOTAL

Testing, Monitoring, Flushing 1 $6,000.00

Emergency Repairs 1 $6,000.00

$12,000.00

Electricity for 4 systems 12 Yearly $200 $2,400

Septic Tank Maintenance/Pumping 1 Yearly $3,000 $3,000

Inspections/Repair 2 Yearly $300 $600

$6,000

Curb and Gutter Maintenance 1 10 years $1,200 $120

Storm Drain Cleaning 1 Yearly $500 $500

$620

Seal Coat 1 4 Years $12,000 $3,000

Patching 1 Yearly $4,100 $4,100

Process in Place, Add Aggregate and Reblot

1 10 Years $80,000 $8,000

$15,100

$33,720$1,466

$122

Roads Annual O&M Costs

ANNUAL OPERATIONS & MAINTENANCE COSTS

TOTAL Annual O&M Costs Annual O&M Per Lot (23)

Monthly O&M Fee Per Lot (23)

WATER

WASTEWATER

STORMWATER

ROADS

Yearly

Water Annual O&M Costs

Yearly

Wastewater Annual O&M Costs

Stormwater Annual O&M Costs

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OPERATION AND MAINTENANCE DETAIL

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SHORT-LIVED ASSET RESERVE

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Conclusions and Recommendations

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The schedule to complete infrastructure construction and to coordinate the first cohort of self-help and workforce housing construction during 2015 is aggressive. However, Thunder Valley has paved the way for an expedited approval process by developing this report in close coordination with the South Dakota USDA Rural Development offices. Thunder Valley has also already begun their workforce training program in sustainable construction practices in preparation for building the first group of single family homes.

The schedule allows for a 30-day PER approval process and then another 30-days to approve funding. After the PER approval, it is recommended that the detailed geotechnical work be undertaken. Soil percolation tests will be done at this time to verify appropriate placement of septic drainfields or mounds. After funding approval, the design team will finalize the detailed design of systems and create the construction documents. An expedited permit set of documents will be issued with applications and appointments set with reviewing authorities.

Community members are ready and waiting to become homeowners in Thunder Valley. Time is of the essence to build a healthy, affordable community that provides not only homes but new job opportunities, healthy food, and spaces for businesses, arts organizations, and education. Wheels are in motion to build, and it is up to the collective of involved organizations to increase the momentum through finding opportunities to expedite approval processes, design processes, and construction processes.

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References

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1. “City of Rapid City Infrastructure Design Criteria” City of Rapid City, 2012 Edition.

2. “Criteria for Design of Public Water Supply Facilities in South Dakota, A Supplement to the Recommended Standards for Water Works” SDDENR, July 1, 1979.

3. “Geologic Map Showing Water-analysis Diagrams and Locations of Wells, Springs, and Test Holes, Hydrogeology of the Pine Ridge Indian Reservation, South Dakota” Department of the Interior United States Geological Survey, 1991.

4. “Hydrogeology of the Pine Ridge Indian Reservation, South Dakota” Department of the Interior United States Geological Survey, 1971.

5. “Recommended Design Criteria Manual Wastewater Collection and Treatment Facilities” SDDENR, March 1991.

6. “Recommended Standards for Wastewater Facilities, Policies for the Design, Review, and Approval of Plans and Specifications for Wastewater Collection and Treatment Facilities (Ten States Standards)” Wastewater Committee of the Great Lakes-Upper Mississippi River Board of State and Provincial Public Health and Environmental Managers, 2004 Edition.

7. “Social/Physical Impacts and Water Consumption Characteristics of South Dakota’s Rural Water Systems”, Water and Environmental Engineering Research Center, South Dakota State University.

8. “Wastewater Engineering: Treatment/Collection/Reuse” Metcalf & Eddy, Inc., George Tchobanoglous, 1979.

Aside from calculations referenced in Appendices, and the four attachments of full reports and case studies (Environmental Report, Equity and Opportunity Assessment, Housing Plan Phase 1, and Constructed Wetland case studies and articles), following are documents referenced within the body of the report:

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AppendicesAPPENDIX A: WATER SUPPLY SUPPORTING DATA, P. 108APPENDIX B: WASTEWATER SUPPORTING DATA, P. 120APPENDIX C: STORMWATER SUPPORTING DATA, P. 152APPENDIX D: FULL BUILD-OUT PLAN, P. 188

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Appendix A: Water Supply Supporting Data

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The supporting data for water supply consists of a written notice of supply allocation, hydraulic modeling information, and the permit required.

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HYDRAULIC MODELLING DIAGRAM AND TABLES (PAGES 110-112)

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Customized Junction Report for Thunder Valley

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Customized Pipe Report for Thunder Valley

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Appendix B: Waste WaterSupporting Data

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The supporting data for wastewater consists of:• EPA permits and one EPA inventory, page 156• Lagoon sizing calculations, page 165• Advantex sizing documentation, page 167• Constructed Wetland memo, page 171• Constructed Wetland sizing calculations, page 173• Treatment to achieve nitrogen reduction to <20mG/L, page 177• Drainfield and mound sizing for septic system, page 178

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CONSTRUCTED WETLAND SIZING CALCULATIONS

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TREATMENT TO ACHIEVE NITROGEN REDUCTION

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DRAINFIELD AND MOUND SIZING FOR SEPTIC SYSTEM

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Mound/Evaporation System Sizing CalculatorRegulatory Guidance from:SDENR Water Supply & Treatment System (Article 74:53): Individual & Small On-site Wastwater Systems

Design Flow: 12,814 gpdPercolation: 60-90 90-120 120 minutes/inch (NRCS Soil Survey Estimate)

Application Rate: 0.39 0.3 0.24 gal/sf-day (74:53:01:37 - Table 6 Yr Around & percolation rates)Aborption Area: 32,856 42,713 53,391 sq ft 1.23 acres

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154

Appendix C : StormwaterSupporting Data

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The supporting data for stormwater consists of a 27-page drainage study and the eight-page permit needed.

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Appendix D: Full Buildout Plan

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Playground

Basketball Court

Bunkhouses

Community Building typ.

Workforce Training

Greenhouses

24’ wide road typ.Single family homes typ.

Shared greenspace

Alleys and driveways typ.

Single family garden typ.

Commercial with apartments above, typ. along frontage (3-story)

Townhomes typ. (2-story)

Retail and live/work apartments (2-story)

Charter School(3-story)

Wastewatertreatment

Overlook

Single family homes typ.

Ropes course

Skatepark

Youth Shelter

Daycare and Fitness Center

Cultural Center and TV Offices

Multifamily residences (3-story)

Workforce Training (2-story)

Pow Wow Grounds

Retail and live/work apartments (2-story)

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