Presentation on theme: "Eastham Water System Water Supply Development Program Board of Selectmen Update April 9, 2012."— Presentation transcript:
Eastham Water System Water 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 Rask Barnstable 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 system compounds.
Principal Conclusions “The Town needs to protect the public health by providing a reliable public water supply from a protected source.” Eastham Wastewater Mgmt Plan GHD Inc., 2009
Wastewater Mgmt Plan GHD, 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 Plan GHD, Inc.
Wastewater Mgmt Plan GHD, Inc. Sewer Service Areas Not a Town-wide system Targeted embayments Town Cove/Nauset Estuary Rock Harbor
Wastewater Mgmt Plan GHD, Inc. Sewer Locations
Wastewater Mgmt Plan GHD, Inc. Limited WW System Cost estimate: $59 Million
Wastewater Mgmt Plan GHD, 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 systems Pharmaceuticals Cleaning Solutions Flame retardants Hormones Metals Insect Repellents Personal 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 MGD Peak Day 2.65 MGD
. Supply Sources NRHS District G District H
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 Modeling Water 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 MGD
NRHS Survey Map
District G MGD
District H 1.30 MGD
District H Town of Eastham NPS
5/4/ McLane Environmental, LLC DRAFT VP-09 OW-1A,B,C,D TPW-1B OW-2A,B,C,D TPW-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 NorthwestSoutheast A D B C Aquitard Till or weathered bedrock Gamma (cps) 8, 16, 32 Inch Normal Resistivity (ohm-m) EM Conductivity (m/Sm) Elevation (ft NAVD88) 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
Phase 1 Fire 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 Connections 95% fire protection
Phase 6 Seashore Area 284 Connections
Service Connections Program
System Cost $111,000 construction cost (includes inflation through construction) Construction in six phases Starting 2015 Two years each Financing done in two-year increments
Betterment Program Every lot assessed based on value Start-up betterment Final betterment
Betterment Program Borrowing Period 20 yrs Interest Rate2% - 4% Betterment Payback20 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