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Eastham Water System Water Supply Development Program Board of Selectmen Update April 9, 2012 PowerPoint Presentation
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Eastham Water System Water Supply Development Program Board of Selectmen Update April 9, 2012

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

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  1. Eastham Water SystemWater Supply Development ProgramBoard of Selectmen UpdateApril 9, 2012

  2. Agenda 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

  3. Why Water? • 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

  4. 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

  5. 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

  6. Sign at Town Hall after August 2011 storm

  7. Why Should We Be Concerned? • 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

  8. Leach field Downgradient well Nitrate Pharmaceuticals c Household Products

  9. Drinking wells intercepting plume at different distances from plume source and therefore showing different concentrations of nitrate

  10. 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

  11. 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

  12. 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

  13. Eastham BOH Well Testing Program • 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

  14. % 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.

  15. Eastham Wastewater Mgmt PlanGHD Inc., 2009 Principal Conclusions “The Town needs to protect the public health by providing a reliable public water supply from a protected source.”

  16. 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

  17. Wastewater Mgmt Plan GHD, Inc. “Wastewater treatment alone will not remediate the existing human health need of safe drinking water.”

  18. Wastewater Mgmt Plan GHD, Inc. Sewer Service Areas • Not a Town-wide system • Targeted embayments • Town Cove/Nauset Estuary • Rock Harbor

  19. Wastewater Mgmt Plan GHD, Inc. Sewer Locations

  20. Wastewater Mgmt Plan GHD, Inc. Limited WW SystemCost estimate: $59 Million

  21. 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.”

  22. 2011 Silent Spring Institute Study“Emerging Contaminants In Cape Cod Private Drinking Water Wells – 2011” • 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

  23. Silent Spring Study: Findings • 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

  24. Why Water? • 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

  25. Water Supply Investigation Program GOAL 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

  26. Town-wide Water System 6667 Lots Served Annual average day 1.00 MGD Summer average day 1.88 MGD Peak Day 2.65 MGD

  27. . Supply Sources NRHS District G District H

  28. Well Development

  29. Geology: Glacial Deposits NW: Sand to ~100’; silt/clay to 400’+ SW: Sand to 400’; silt and clay layers District G NRHS Approximate Salt Water Interface District H N

  30. Nauset Lens Groundwater Model 9

  31. Groundwater Modeling of Potential Water Supply Withdrawals

  32. 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

  33. NRHS Site0.882 MGD

  34. NRHS Survey Map

  35. District G0.995 MGD

  36. District H 1.30 MGD

  37. District H NPS Town of Eastham NPS

  38. District H – Surveyed Site Plan VP-11 OW-2A,B,C,D TPW-2C OW-3A,B,C, TPW-3B OW-1A,B,C,D TPW-1B OW-4 A,B,C VP-09 VP-01 McLane Environmental, LLC 9/24/2014 DRAFT 48

  39. District H – Site Stratigraphy Northwest Southeast Water Table- May 2, 2011 A Aquitard B Aquitard C Aquitard Elevation (ft NAVD88) Gamma (cps) 8, 16, 32 Inch Normal Resistivity (ohm-m) D EM Conductivity (m/Sm) Distance (ft) Aquifer (Fine to medium sand with traces of coarser sand and gravel) Aquitard(Silty clay and silt / Silty sand ) Till or weathered bedrock 49 McLane Environmental, LLC

  40. 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