Town Council Mtg Oct 24 2011 Lat Oct 24 Final

8/3/2019 Town Council Mtg Oct 24 2011 Lat Oct 24 Final

1/17

TOWN OF MANSFIELD, CT

DEPARTMENT OF PUBLIC WORKS

WATER SOURCE PROJECTSPECIAL TOWN COUNCIL MEETING

WORK SESSIONMonday, October 24, 2011


2/17

OUTLINE

Mansfields Water Supply Needs

Water Supply Alternatives

Evaluation of Alternatives Permitting Requirements

Selected Site(s)

Partnership with UConn

Water Supply Development Process


3/17

MANSFIELDS WATER SUPPLY NEEDS

Four Corners Area

- 500 acres, 60 parcels

- 59,000 179,000 gallons per day

Assisted Living

UConn & Town - seeking 0.5 to 1.0 MGD


4/17

Well

Cedar Swamp Area

Willimantic River

Mansfield Hollow

CT Water Interconnection

Windham Interconnection

WATER SUPPLY ALTERNATIVES


5/17


6/17

Water Quantity

Water Quality

Permitting

Other Parties

Infrastructure

Cost

Reliability & Redundancy

ALTERNATIVES ANALYSISFACTORS TO CONSIDER


7/17

PERMITTING

Groundwater Interconnections

DEP Diversion Diversion

DPH

Site Suitability

Quantity & Quality

RedundancyStorage

Design Review

Sale of Excess Water Permit

Redundancy

StorageDesign Review

DPH/DPUC Certificate ProcessCertificate Process

Extension of UConn System

Inland

Wetlands

Setbacks

Stormwater

P&ZZoning

Access


8/17

Projected Demand 170,000 gpd

15% Margin of Safetywith largest source off-line

Backup source

Water Storage

Domestic Needs

Fire Fighting Needs

RELIABILITY AND REDUNDANCY


9/17

CT WATER INTERCONNECTIONFactor Advantages DisadvantagesQuantity of Water

CT Water has indicated that they have available

water to provide to UConn (0.5 MGD) and the

Town (0.5 MGD).

DPH questions if CTWater has available

additional water.Quality of Water

CT Waters 2009 Water Quality Report for its

Northern Region-Western System indicated that

the system met all MCLs in 2009.DEP Diversion Permit

CT Water interconnection would involve an

interbasin transfer, which could complicate the

Diversion permitting process.DPH Regulations/

Permits/ApprovalsThe Four Corners distribution system would be an

extension of the CT Water system; a Certificate of

Public Convenience and Necessity is not needed.

To obtain a Sale of Excess Water Permit, CT

Water needs to provide DPH with information

showing that they have adequate water supply.

Reliability/RedundancyThe Four Corners distribution system would be an

extension of the CT Water system, and would be

interconnected with the UConn system, and would

thus benefit from the reliability/redundancy in the

CT Water and UConn systems.

Water Storage and Fire

Protection

The Four Corners distribution system would be an

extension of the CT Water system, and

interconnected with the UConn system, and would

thus benefit from the storage in both of those

systems.Local Permitting There is public concern that a CT Water pipeline extensionalong Rt 195 will spur unwanted development.

InfrastructureAlthough the alternative would include more than 5

miles of pipeline, CT Water has proposed to UConn

that they pay for this pipeline.Property Purchases No property purchases required.Other Parties Numerous entities are involved: CT Water,

UConn, and Tolland.


10/17

EAGLEVILLE LAKE AREAFactor Advantages DisadvantagesWater Quantity Significant depths of good aquifer

material along the Willimantic River

Eagleville Lake reduces the potential of

groundwater withdrawals on fish habitat;

which could result in relatively high

allowed withdrawals.

Ongoing concerns about the impact of UConns existing wells

along the Willimantic River could impact the allowable

withdrawal from a well; however, Eagleville Lake reduces the

potential impacts on fish habitat.

Water Quality For Site EP-5 (Eagleville Preserve) thereare no identified water quality risks.

For Site EP-1 and EP-2, there is a need to investigate the

possible impact on water quality of the use of agricultural

chemicals and the former wastewater disposal on the adjacent

property.

For Site EP-3, there is a need to investigate the possible

impact on water quality of gravel pit on the adjacent property.DEP DiversionPermitting A well near Eagleville Lake is expected torequire less permitting effort that a new

well upstream.Diversion permitting could be complex relative to MansfieldHollow area because of concerns that additional groundwater

withdrawals would impact streamflow and thus fisheries.DPH Requirements/

Permits/ApprovalsThe Four Corners distribution system would be an

extension of the UConn system; a Certificate of Public

Convenience and Necessity is not needed.Reliability/Redundancy The Four Corners water system would be an extension

of the UConn system, and would thus benefit from the

reliability/redundancy (in terms of supply and storage)

in the UConn system.Water Storage and Fire

ProtectionThe Four Corners water system would be an extension

of the UConn system, and would thus benefit from the

storage in the UConn system.Infrastructure Relatively long pipeline extensions would be needed for

several of the Eagleville Lake Area alternatives.Property Purchases Potential well site EP-5 is on a Town-owned parcel.

Potential well site EP-4 is on a State-owned parcel.Potential well sites for EP-1, EP-2, and EP-3 are on private

property, and would thus require purchase of property.Other Parties UConn, for a wheeling agreement and

interconnection.


11/17

POTENTIAL WELL SITES

Initial Evaluation(# of properties)

Site Planning and EnvironmentalAssessment

Cedar Swamp 2 None

Mansfield Depot Area 3 River Park

Mansfield Hollow Area 3 Southeast School Site

Eagleville Lake Area 5 Eagleville Preserve


12/17

!.

!.

!.

!.

!.

!.

!.

MH-3 Well Site

MANSFIELD

UConn FentonRiver Wells

MD-3 Well Site

Four CornersPlanning Area

EP-5 Well Site

UConn Water System

Circle K/Gulf

UConn Landfill

Eagleville Garage

Spring Manor Farm

G.M. Thompson & Son

Mansfield Town Landfill

Mansfield Town Landfill

195

32

44

275

31

89

320

Storrs

Stafford

Middle

Worm

woodHill

Chaffe

eville

Gurleyville

Browns

Woo

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nd

Eagle

ville

Maple

Main

Birc

h

MansfieldCity

Forest

Root

Davis

Mulberry

Baxter

South

Eaglevill

e

Dog

Warrenvill

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Sprin

gHill

Bonemill

Stonehou

se

East

C

o d fi s

h F

a l l s

Clover Mill

Coventry

HanksHill

Separatist

HuntingLodge

LewisHill

OldEagleville

Ravin

e

BrighamTavern

Cooper

Depot

Summit

RipleyHill

OldTu

rnpike

High

Lak

e

Riv

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w

Bundy

CedarS

wamp

Cemetery

Merrow

Wildwood

Sc

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Wall

Fairf

ield

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MountH

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Alumni

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PineLake

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Mansfield

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KingHill

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Fields

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Depot

Legend

Existing Water Main

Proposed Water MainsFour Corners Planning Area

UConn Water System

Town Boundary

Potential Well Sites

!. Potential Contamination Sources

0 1,500 3,000750Feet

Mansfield, CT

All Data Supplied by the State ofConnecticut Department ofEnvironmental Protection

Figure 1Water Supply Alternatives

Mansfield, Connecticut

May 2011


13/17

#V

#V

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#V

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#V

#V#V

#V

#V

#V

#V

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#V

LOT 29-54-20(TOWN)

RAILR

OADTRACKS

STAFFORDRD(R

T32)

100 YR FLOODELEVATION(272')W

ILLIM

ANTIC

RIVER

POTENTIAL TEST WELLLOCATION #1

200' BUFFER ZONE

LOT 29-54-19-2(TOWN)

RESIDENTIAL HEATINGOIL TANK

POTENTIAL TEST WELLLOCATION #2

270

320

282

282

270

280

318

278

272

316

268

294

288

274

276

314

274

270

272

312

272

278

2

86

266

266

276

274

310

328

280

266

308

272

274

266

268

266

306

282

304

326

280

270

302

278

276

270

324264

272

300

322

268

298

266

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270

264

292

286

284

282

288

270

274

296

290

294

268

274

272

276

278

268

0 50 10025Feet

Mansfield, CT

All Data Supplied by the State ofConnecticut Department ofEnvironmental Protection

Eagleville PondPotential Well Sites

Mansfield, Connecticut

October 2011

Legend

#V Wetland Flag

150 ft Wetlands Setback

Wetlands_Town_Buffer

Stream

Water Body

Wetlands

Natural Diversity Circle

Required 200ft Sanitary Radius

Potential Contamination Sources


14/17

Advantages Above 100-year flood level

More than 50 ft from annual high water mark

200 ft radius sanitary control

Disadvantages

Downstream of dam; flow sometimes only WWTP effluent

~19,100 feet of pipeline needed to UConn

CTWater proceeding with 100,000 gpd well across river

185 psi static discharge pressure at well

EAGLEVILLE PRESERVE SITE


15/17

River Park

Limited locations for a well Former site of wastewater infiltration structures

Close to UConns wellfield; could impact permitting

Nearby wastewater pump station overflows

Within Natural Diversity Area

Southeast School Site ~6.5 miles of pipeline needed

May need sanitary easement from Army Corp. for 200 ft radius

School might be expanded

Within Natural Diversity Area

OTHER SITES


16/17


17/17

Alternatives Analysis (Jan 2011) Site Planning and Environmental Assessment (May 2011)

EIE (Sept Spring 2011)

Small Diameter Test Wells & DPH Site Approval (Oct-Dec 2011)

Large Diameter Test Well & Groundwater Modeling

Diversion Permitting

Design

Bidding

Construction

WATER SUPPLYDEVELOPMENT PROCESS

Documents

Town Council Mtg Oct 24 2011 Lat Oct 24 Final