Lake Waukewan Watershed
Transcription
Lake Waukewan Watershed
Lake Waukewan Watershed Protecting Source Water for the Town of Meredith The Watershed Drains into Lake Winnipesaukee Spans over 5 towns: Meredith, Center Harbor, New Hampton, Ashland and Holderness Comprised of 3 ponds and Lake Winona that feeds into Lake Waukewan via the Snake River Has an area of 8,297.8 acres or 13 square miles. Lake Waukewan Municipal water supply for the Town of Meredith Has an area of 953 acres with an average depth of 22 feet and 8 miles of shoreline that is largely developed. The lake is fed by the Snake River and 5 other tributaries. There is a dam that controls the outflow of the lake into Winnipesaukee. Due to the large land to lake area, it has a low flushing rate of .6 times/yr (NH median 3times/yr). Lake Waukewan Management Plan Adopted by the Town of Meredith in June 2005 Prepared by Jennifer Palmiotto and Waukewan Watershed Advisory Committee with the assistance of many others. Takes into account it is a share recreational resource as well as the drinking water supply. Used as a road map to guide decision making and management strategies to address potential risk to water quality. Waukewan Watershed Advisory Committee consists of representatives from the different communities and is advisory to the Meredith Board of Selectmen. Potential Pollution Sources Land disturbance from site developmentstormwater runoff from increased impervious and land disturbance Recreation activities- public beach, park, boat launch and HOA facilities. Wastewater disposal (septic systems)- large majority of watershed and lakefront served by private wastewater treatment Lawn care practices- expansive lawns, little or no shoreline buffer and use of fertilizers and pesticides Transportation corridors- conduits for stormwater, winter maintenance SEPTIC SYSTEMS THREAT TO WATER QUALITY Failing or substandard septic systems are a major threat to water quality due to the leaching of nutrients and pathogens (bacteria) into ground and surface waters. Phosphorus and Nitrogen are nutrients that contribute to algal blooms and aquatic weeds. Risk of Septic System Pollution Conducted a Septic Risk Analysis using GIS. Study area consisted of all parcels with septic systems within 250 feet landward of Waukewan. Collected data and considered 3 known attributes for all systems. Inventoried Center Harbor and New Hampton shorefront septic systems. Innovative Approaches to Address and Mitigate Risk Evaluate feasibility of expanding sewer system. Conduct public outreach and education, a multi-town approach. Identified and evaluate existing rules for subsurface wastewater disposal systems. Draft health regulation to address inspection and replacement of select systems. Evaluate funding options to replace failed systems. Identify Existing Rules & Requirements Env-Wq 1025 requires assessment of waterfront properties (not systems) prior to P&S agreement. Env-Wq 1003.12 requires a new system is designed when flow increases but only installed at the time of failure. RSA 485-A:2 IV defines failure of subsurface systems if waste disposal system does not contain or treat (Env-Wq 1002.30). Identify Shortcomings and Gather Information No real evaluation of septic systems is required. Eliminate the wait for failure approach and install the system. Require inspections of systems to determine if containment and treatment of wastewater is occurring. Meet with various experts. Refer to strategies identified in Watershed Management Plan. Drafting a Regulation Conduct Public Education and Outreach Mailings to homeowners regarding septic system maintenance (began in 2008), workshop invites, updates to regulation, etc. Information added to town’s website. Educational workshops and meetings hosted by the town and HOAs Several newspaper articles regarding septic systems. Public meetings Selectmen and WWAC to discuss regulation. Draft Regulation for Subsurface Wastewater Disposal Systems 1. 2. No valid design approval on file with NH DES requires disposal system be evaluated by qualified person that existing system is not in failure. No valid design approval on file with NH DES and building permit request to expand lot coverage but not living space, a septic design is required to ensure future space is reserved to upgrade system. 3. 4. When a building permit request to expand the number of bedrooms is submitted, a design approval is required with building permit and operation approval prior to CO. When a building permit request to expand square footage of living space is submitted and no valid design is on file with NH DES, a design approval is required with building permit and operation approval prior to CO Status of Draft Regulation Needs to be adopted by the BOS. Has been reviewed at a few BOS workshops. Still a draft with a few details to be settled on. Would be the first health regulation to address septic systems in the state. Questions