eastham water system water supply development program board of selectmen update april 9, 2012
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Eastham Water System Water Supply Development Program Board of Selectmen Update April 9, 2012. Agenda. Why water? Benefits of a water system Water quality studies documenting conditions Relationship with wastewater planning Water supply investigations Water system preliminary design - PowerPoint PPT PresentationTRANSCRIPT
Eastham Water SystemWater Supply Development
Program
Board of Selectmen Update
April 9, 2012
Why water? Benefits of a water system Water quality studies documenting
conditions Relationship with wastewater planning Water supply investigations Water system preliminary design Cost forecasting and allocation
2
Agenda
Drinking water wells in close proximity to septic systems
Water quality is steadily declining from septic system cross-contamination
Documented in several studies No official water quality monitoring,
management program for private wells
Why Water?
Provide clean, potable water from protected and managed sources remote from septic systems, and other activities that can impact private well water quality
Strict EPA/DEP quality monitoring program Provide Town-wide Fire Protection Reduce Home-owners Insurance Costs by
$400-$500/year for Average Home
Why Water?
Long-term community investment in infrastructure
Water System Immune to Power Outage as happened in August 2011
You’ll know what you’re drinking Regular testing under strict guidelines Annual public reporting
Why Water?
Sign at Town Hall after August 2011 storm
Nitrates are a risk factor for infants, but are also an indicator
Larger concern: other wastewater components
Not normally tested for, are expensive, but are often present along with nitrates
Why Should We Be Concerned?
Nitrate
c
Downgradient well
Leach field
Household Products
Pharmaceuticals
Drinking wells intercepting plume at different distances from plume source and therefore showing different concentrations of nitrate
Projected Use of Innovative/Alternative On-site Sewage Treatment Systems in Eastham, Under Current Regulations and Policies
Susan RaskBarnstable County Department of Health and
Environment
2007
Bedroom density and nitrate levels
“Short circuiting” is occurring due to small lot size and large number of wells and septic systems;
“45% of lots exceed 4 BR’s/Acre model”
High number of samples > 2mg/L validates that entire groundwater system is showing nitrogen impacts from septic systems – not likely to improve
Bedroom density and nitrate levels
70% of single family residences (7 out of 10 homes) exceed the Title 5 standard for density on nitrogen sensitive lots – Eastham 2012
9,600 private wells tested since 2003 Approximately 1,000 per year Test only for Nitrates as low-$$ indicator Data analyzed by geographic map areas Clear geographic variability
North Eastham most severe South Eastham least severe
Eastham BOH Well Testing Program
% of Wells > 5 ppm Nitrates
Red > 30%Orange 20 – 30%Yellow 10 – 20%Green 0 – 10%Remember: Nitrates are an indicator
of other septic systemcompounds.
Principal Conclusions
“The Town needs to protect the public health by providing a reliable public water supply from a protected source.”
Eastham Wastewater Mgmt PlanGHD Inc., 2009
Wastewater Mgmt PlanGHD, Inc.
• Nearly all properties served by a well and septic system on the same lot
• Private wells are becoming impacted by septic tank effluent
• Contamination is indicated by elevated nitrate
• Protect public health with a public water supply
“Wastewater treatment alone will not remediate the existing human health need of safe drinking water.”
Wastewater Mgmt PlanGHD, Inc.
Wastewater Mgmt PlanGHD, Inc.
Sewer Service Areas• Not a Town-wide system
• Targeted embayments• Town Cove/Nauset
Estuary• Rock Harbor
Wastewater Mgmt PlanGHD, Inc.
Sewer Locations
Wastewater Mgmt PlanGHD, Inc.
Limited WW SystemCost estimate:$59 Million
Wastewater Mgmt PlanGHD, Inc.
“The human health wastewater needs are very clear and are best met with the development of a public water supply system from a protected water source.”
Sampled private wells across the Cape Tested for “Emerging Contaminants” from
septic systemsPharmaceuticals Cleaning SolutionsFlame retardants HormonesMetals Insect RepellentsPersonal Care Products
Possible health effects, unregulated, untested
2011 Silent Spring Institute Study
“Emerging Contaminants In Cape Cod Private Drinking Water Wells – 2011”
27 different contaminants detected More nitrate = more contaminants
= higher concentrations 3 pharmaceuticals at highest levels in the U.S. There are no standards for these
contaminants Consider home filtration if nitrate >0.5 ppm Did not test for bacteria and viruses
Silent Spring Study: Findings
Provide clean, potable water from protected and managed sources remote from septic systems
Provide Town-wide Fire Protection Reduce Home-owners Insurance Costs
by $400 - $500/year for Average Home Water System Immune to Power
Outage as Happened in August 2011
Why Water?
FY 2010 Annual Town Meeting, Article 17 Conduct pump tests to establish the
quantity and quality of water available from…Districts G, H and Nauset Regional High School and perform permitting necessary to provide up to 1 MGD from each site.
Evaluate feasibility of obtaining 0.5 MGD or more water from Orleans
32
Water Supply Investigation Program
GOAL
Town-wide Water
System
6667 Lots Served
Annual average day 1.00 MGD Summer average day 1.88 MGDPeak Day
2.65 MGD
.
Supply Sources
NRHS
District G
District H
Well Development
Approximate Salt Water Interface
N
NW: Sand to ~100’; silt/clay to 400’+SW: Sand to 400’; silt and clay layers
District G
District H
NRHS
Geology: Glacial Deposits
9
Nauset Lens
Groundwater Model
Groundwater Modeling of Potential Water Supply Withdrawals
Ground Water ModelingWater Supply Goal
Long-term effects on aquifer conditions
100-year period modeled Use annual average demand (1.0
MGD) Represents average demand at full
build-out of system
NRHS Site
0.882 MGD
NRHS Survey Map
District G
0.995 MGD
District H
1.30 MGD
District H
Town of Eastham
NPS
NPS
04/21/23 48McLane Environmental, LLCMcLane Environmental, LLCDRAFT
VP-09
OW-1A,B,C,DTPW-1B
OW-2A,B,C,DTPW-2C
OW-3A,B,C,TPW-3B
OW-4 A,B,C
VP-01
VP-11
District H – Surveyed Site Plan
Aquitard (Silty clay and silt / Silty sand )
Aquifer (Fine to medium sand with traces of coarser sand and gravel) 49
Northwest Southeast
A
D
B
C
Aquitard
Aquitard
Aquitard
Till or weathered bedrock
Gamma (cps)
8, 16, 32 Inch Normal Resistivity (ohm-m)
EM Conductivity (m/Sm)
Ele
vati
on
(ft
NA
VD
88)
Distance (ft)
McLane Environmental, LLC
Water Table- May 2, 2011
District H – Site Stratigraphy
Groundwater and Vernal Pool Monitoring
Monitor water levels in surface water, peat, and water table
Monitor three nearest vernal pools VP-01, VP-09 and VP-11
VP-9 and OW-4 Well Cluster
Vernal Pool VP-09
Orleans as a water supply?
Eastham can be entirely self-sufficient
Not enough available from Orleans to meet Eastham’s demands
Far less costly for Eastham to supply its own water
Interconnection for emergencies
Water System
Preliminary Design.
Phase 1
• Wellfields
• Transmission Mains
• Storage Tanks
• 1,391 Connections
Phase 1Fire Protection
•1000’ radius from mains
•Lower insurance rates
•Encompasses 75% of all lots
Fire Protection and Home Insurance Applies to all properties w/in 1000’ of system
and 5 miles of fire station
Wellfleet experience
ISO Rating dropped from Category 9 to 4
Reduced insurance for $400,000 home by $500 - $700/year
Projected insurance decrease for Eastham: $400 - $500/yr (for $400,000 home)
Phase 21126 Connections
95% fire protection
Phase 3
1117 Connections
Phase 4
1079 Connections
Phase 5
1502 Connections
Phase 6Seashore Area
284 Connections
Service Connections Program
System Cost
$111,000 construction cost(includes inflation through construction)
Construction in six phasesStarting 2015Two years each
Financing done in two-year increments
Cost Allocation Approaches
Taxes
Betterments
Connection Fees
Betterment Program
Every lot assessed based on value
Start-up betterment Final betterment
Betterment Program
Borrowing Period 20 yrsInterest Rate 2% - 4%Betterment Payback 20 yrs
Pursue grants and low-interest loans (SRF, USDA) and abatements
Financing the System
Low Interest Loans or Conventional Loans/ Grants
Betterment
Financing
$17,000 for 20 years at 2% (for average property at $400,000)
Average annual betterment: $400-$600/year
Homeowners insurance savings: $400 - $500/year
Water fees (if connected): $200/year Abatement program
Discussion