BBaacckkggrroouunnddHampton Roads Sanitation District

(HRSD), a political subdivision of theCommonwealth of Virginia, is located insoutheastern Virginia. HRSD was createdby public referendum in 1940 to eliminatesewage pollution in the tidal waters of theChesapeake Bay. HRSD’s service areaincludes 17 cities and counties of southeastVirginia, an area of over 3,100 squaremiles with a population of 1.5 million. Itoperates nine major wastewater treatmentplants in Hampton Roads and four smallerplants on the Middle Peninsula having acombined capacity of 231 million gallonsper day (mgd).

Water reuse has been a goal at HRSDsince the mid-1980s, when the districtbegan discussions with water purveyors touse reclaimed water for nonpotable appli-cations in lieu of potable water. Theseefforts came to fruition in 1996 when theAmoco Yorktown Refinery (subsequentlysold to Giant Industries, Inc.) expressedinterest in using reclaimed water. At thattime, the refinery was using potable watersupplied by the Newport News WaterWorks as its source of cooling and processwater. Projected increases in the cost ofpotable water led the refinery to seek a lessexpensive water source. The cost toupgrade treatment at the refinery’s own1.5 mgd wastewater treatment facility rep-resented a large capital investment by the

refinery; hence, a logical option was toconsider the use of reclaimed water fromHRSD’s York River Treatment Plant (YRTP),located adjacent to the refinery.

Negotiations were soon underway and acontract between HRSD and the refinerywas signed in December 2000. The con-tract included a 20-year agreement forproduction and delivery of reclaimed waterto Giant Industries’ Yorktown Refinery andwater quality objectives based on the usesof the water at the refinery. Construction offacilities at the YRTP to produce 0.5 mgd ofreclaimed water for use at the refinerybegan soon after that time, and the projectbecame operational in July 2002. Duringthe first year of operation, reclaimed wateruse at the refinery averaged about 0.4mgd, which is 80 percent of the project’santicipated usage of 0.5 mgd. The waterreuse facilities are collectively called theJames River Water Reclamation Facility.

PPrroojjeecctt DDeessccrriippttiioonnThe Yorktown Refinery, built in 1956,

processes 60,000 barrels (2.5 mgd) ofcrude oil per day to produce gasoline,diesel fuel, heating fuel, and other prod-ucts. The refinery categorizes its non-potable water as either service water orboiler feed water. Reclaimed water is usedfor the following service water applications:cooling; crude oil desalting; coke cutting;miscellaneous uses such as rinsing and

Hampton Roads Sanitation District

Reprinted with permission from the WateReuse Association

chemical mixing; charge water for the fireprotection system when it is not in use (YorkRiver water would be used during actualfirefighting); and irrigation of trees.

The source of the reclaimed water isHRSD’s York River Treatment Plant (YRTP),located in York County. The influent to theplant is mostly domestic wastewater, asthere is little industrial wastewater input tothe sewerage system. Not including theaddition of sidestream treatment to pro-duce reclaimed water for the refinery, theYRTP has conventional activated sludgesecondary treatment, chemical phosphorusremoval, and disinfection using sodiumhypochlorite. The effluent is dechlorinatedprior to discharge to the York River. Thewastewater treatment plant has a permittedcapacity of 15 mgd and a current averageflow of about 10.5 mgd.

The reclaimed water agreement betweenHRSD and the refinery consummated in2000 included water quality limits recom-mended by a committee of regional juris-dictions (including HRSD), the refinery, andthe Virginia Departments of Health andEnvironmental Quality. The reclaimedwater limits include the following:

• Reclaimed water quantity: 0.5 mgd;

• Chemical oxygen demand: <40 mg/L;

• Total suspended solids: <10 mg/L;

• NH3; <2.0 mg/L;

• Phosphorus: <2.0 mg/L;

• Turbidity: <5 NTU;

• Fecal coliforms: <200/100 mL;

• Chlorine residual: ≥ 0.5 mg/L;

• pH: 6.0-9.0;

• Calcium: no significant increase; and

• Sodium: no significant increase.

Water quality data from YRTP indicatedthat the existing activated sludge treatment process could not consistentlymeet the ammonia limit during cold weather and could not meet the turbiditylimit on a consistent basis. After investigat-ing several ammonia removal processes,biological nitrification using a sequencingbatch reactor (SBR) was selected as themost reliable and cost-effective technologyto produce reclaimed water for the refinery’s applications.

Prior to conception of this project, HRSDinvestigated the possibility of adding filtra-tion at its wastewater treatment plants toproduce water appropriate for reuse appli-cations. Pilot plant studies conducted in1998 to evaluate the performance of acloth-membrane automatic backwash diskfilter indicated that the filter was capable of

York RiverTreatment Plant

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reliably producing effluent having turbidityless than 1 NTU. Thus, a cloth media diskfilter was selected as the tertiary filtrationunit process for the treatment of reclaimedwater to be used at the refinery.

The selected reclaimed water treatmenttrain, which provides 0.5-mgd capacitysidestream treatment of primary effluent atYRTP, is as follows: biological oxidation andnutrient removal using an SBR; an equal-ization tank; disinfection (chlorine is addedto the equalization tank); filtration; andfinal disinfection. The product water ispumped through a 2,800-foot pipeline toa 3.6 million gallon storage tank at therefinery. Primary effluent was chosen oversecondary effluent as the source water tothe reclaimed water treatment systembecause the higher BOD concentration inprimary effluent results in a stable concen-tration of heterotrophic and nitrifying bac-teria in the SBR, thus ensuring sufficientbiomass to produce a settleable floc.

Because YRTP normally nitrifies duringthe warmer months, it was originally antici-pated that the SBR would be operated onlyin the winter. It has since been determinedthat it is less expensive to operate the unityear round. The reclaimed water facilitieswere designed so they could be relocatedto another site in the event that YRTPimplements full scale nitrogen removal inthe future.

The quality of the reclaimed water pro-duced at the James River WaterReclamation Facility is considerably betterthan that required by the 2000 agreementand easily meets all reclaimed water treat-ment and quality requirements containedin the most current Virginia Department ofEnvironmental Quality draft regulations forirrigation and industrial uses (i.e., cooling,boiler feed, process water, and fire protec-tion). Average values for selected parame-

ters and constituents in the product waterare as follows:

• pH: 7.0;

• Fecal coliforms: <1/100 mL;

• Turbidity: 0.7 NTU;

• Total suspended solids: <1 mg/L;

• Biological oxygen demand: 4 mg/L;

• NH3: 0.4 mg/L; and

• Total phosphorus: 1.4 mg/L.

PPrroojjeecctt BBeenneeffiittssThe use of reclaimed water at the

Yorktown Refinery results in reduced coststo the refinery for process water while pro-viding a drought proof source of water. Atthe same time, Newport News WaterWorks conserves its potable waterresources, and HRSD reduces the nutrientload released to the York River, which is atributary of the Chesapeake Bay.

FFuunnddiinngg aanndd CCoossttssThe total capital costs of the project are

estimated to be $2.6 million.Approximately $1.6 million of the total willbe funded through the Virginia DEQ’sWastewater Revolving Loan Program. Thisis the first water reuse project fundedthrough this program. The O&M costs forthe first year of operation (fiscal year 2003)are estimated to be between $135,000and $150,000. However, the avoidedtreatment costs associated with removing0.5 mgd from the conventional activatedsludge process are expected to be as muchas $60,000. Thus, the additional cost asso-ciated with the new sidestream treatmentsystem, not including existing O&M costs,is anticipated to be about $80,000 to$90,000 per year. Operational costs willbe borne by the refinery.

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HRSD is selling the water to the refineryat cost to recover only the additionalinvestment (capital and O&M costs)incurred to treat and transport the water tothe refinery. The current reclaimed waterrate of $1.50/1,000 gallons is based onfull recovery costs over a 20-year period.The rate will be reevaluated after threeyears but in no case will exceed the cost ofpotable water, which currently is$3.25/1,000 gallons.

PPootteennttiiaall FFuuttuurree UUsseessA potential future use of reclaimed water

at the refinery is boiler feed water. Pilottesting concluded that HRSD’s reclaimedwater could be treated by reverse osmosis(RO) to meet boiler feed water require-ments. The refinery has installed RO facili-ties and is embarking on a one year fullscale operation to evaluate the use of ROtreated reclaimed water as boiler feed.During this period, all of the reclaimedwater produced at YRTP will be used forboiler feed. This use, in addition to theservice water uses, ultimately may requireexpansion of HRSD’s facilities to accommo-date higher flows and presents issues asso-ciated with ability to meet peak demands,maintenance of consistent pH, and dispos-al of reject water from the RO system.Current and future uses could result in total

reclaimed water use at the refinery as highas 1.0 mgd during peak operation.

HRSD also is pursuing the use ofreclaimed water from some of its otherwastewater treatment facilities. Projectsbeing considered include: providingreclaimed water to the Virginia Departmentof Transportation (VDOT) for tunnel wash-ing; irrigation at a planned golf course inthe City of Norfolk; landscape irrigation atOld Dominion University; using reclaimedwater at the Southeastern Public ServiceAuthority’s waste-to-energy steam andpower plant in Portsmouth; and use at anew gas fired steam plant at the U.S.Navy’s naval amphibious base in VirginiaBeach.

The VDOT project has the potential fordevelopment of a bulk distribution market.HRSD will pursue bulk distribution withlandscapers, municipalities, contractors,and others who need large quantities ofnonpotable water for irrigation, cleaning,surface wetting, and industrial uses.

For further information, contact:Hampton Roads Sanitation District, 1436Air Rail Avenue, Virginia Beach, Virginia23455-3002.

SequencingBatch Reactor

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