AUBURN LAKE TRAILS/GEORGETOWN DIVIDE (PUD), California
Carmody Client
PROBLEM
The Auburn Lake Trails Subdivision in California was developed during the 1970s and 1980s as a recreational community near Auburn Lake, with more than a 1,000 relatively small lots in an area with shallow, low-permeability soils and steep topography. When developers discovered that local soils could not treat the waste adequately to protect water resources upon full build-out, they proposed building a centralized sewage collection and treatment system. However, it was opposed by residents as too costly.
SOLUTION
The community authorized the Georgetown Divide Public Utility District (PUD) to design and manage conventional and advanced treatment individual and clustered wastewater systems. The PUD developed an approach that links the required performance levels for treatment systems to health and environmental risk and where maintenance and monitoring schedules depend on the system type.
RESULTS
Of the 134 septic tanks inspected in 2009, five were found to be defective and were replaced. The inspection and management program has prevented onsite system malfunctions and has been an effective alternative to costly centralized sewers. The annual inspection of all systems provides for early detection of problems that could lead to a malfunction. Water quality sampling since 1985 has found no degradation of groundwater or surface water.
Of the 999 systems in the subdivision, most of them (63%) are more than 20 years old, and 36% are more than 30 years old. Only 10 systems have malfunctioned in the last 25 years; malfunctions were mostly due to tree roots, hydraulic overloading, and other problems such as improper grading, construction activities, etc.
By identifying the location of systems and ensuring their proper operation, the community can make smart decisions to accommodate residential development.
JAMESTOWN, RHODE ISLAND
Carmody Client
PROBLEM
Jamestown is a small, island town dependent on private drinking water wells and individual wastewater systems. Poorly maintained onsite wastewater systems on undersized lots with high seasonal water tables were affecting groundwater quality. Studies revealed that 32% of the wastewater treatment systems in the area were contributing to nutrient and pathogen problems in private water wells (Legislative Press and Public Information Bureau, 2006).
SOLUTION
Jamestown adopted an ordinance requiring routine inspections of individual wastewater systems. A High Groundwater Table District also guides future development to protect drinking water quality.
RESULTS
To date, 94% of all septic systems have had an initial maintenance inspection. Of the systems inspected:
- 35 failed (2%)
- 85 (5%) were found to be substandard systems (e.g., cesspools, systems with
steel tanks)
- 1,488 passed (93%)
- Since 2003, 50 systems have been subject to repair/replacement actions
initiated by the town.
Property owners are responsible for ensuring that their system is operating properly and that it is maintained in good repair. Systems that do not meet applicable performance requirements can be subject to a repair or replacement order. Addressing malfunctioning systems helps to reduce nitrogen and pathogen pollution that pose threats to Jamestown’s drinking water sources.
PEÑA BLANCA, NEW MEXICO
PROBLEM
Outdated, neglected, or nonexistent wastewater systems posed a public health risk to the 800 citizens of Peña Blanca, New Mexico. Open cesspools and seepage pits emptied into yards and irrigation canals. Surveys revealed that 86% of the individual wastewater systems needed repair or replacement. Residents rejected a proposed centralized sewer system that would have cost $3.1 million.
SOLUTION
The community opted to repair or replace 133 of the existing 185 treatment systems with the water and sanitation district serving as the operator/manager of the upgraded and new facilities.
RESULTS
"The decentralized wastewater option was less than half of the projected cost of central sewage treatment for the 133 homes served by repaired or replaced systems. Sewage surfacing and cesspool discharges throughout the community no longer occur. Post-construction groundwater monitoring found nitrate levels at 1 mg/L or less in the project area, far below the 10 mg/L standard for groundwater used as drinking water."
More EPA Studies
OTTER TAIL LAKE, MN
KEUKA LAKE WATERSHED, NY
KEUKA LAKE WATERSHED, NY
The District’s actions resulted in documented water quality improvements. Surface water monitoring of the lake has revealed declining phosphorus and algae concentrations and overall improved water quality. Nitrate concentrations have dropped from 1 mg/L to approximately 0.2 mg/L; Secchi depth has increased from 2.4 feet to about 4 feet.
KEUKA LAKE WATERSHED, NY
KEUKA LAKE WATERSHED, NY
KEUKA LAKE WATERSHED, NY
Water quality monitoring results indicate very good lake conditions, though runoff from stormwater and agricultural sources after storm events can result in high bacteria levels. The relatively clear water in the lake contains low nutrient levels and supports excellent fisheries. Monitoring results from 2005–2009 show lake water quality improving or holding steady for nearly all parameters. The local lake association attributes this progress, in part, to the septic system inspection program.
ALBEMARLE REGION, NC
KEUKA LAKE WATERSHED, NY
ALBEMARLE REGION, NC
Local officials note that the management entity has prevented system malfunctions through more rigorous design, inspection, and operation/maintenance requirements. In the early 1990s, estimates of system malfunctions ranged as high as 30%. During 2007–2008, the program inspected 2,153 of the 4,240 systems under its management purview, and fewer than five of the newly installed systems were found to be malfunctioning. New system installations and increasing the number of properly functioning systems through inspections will help to reduce nutrient pollution in the Albemarle watershed.
FAIRFAX COUNTY, VA
THE SEA RANCH, CALIFORNIA
ALBEMARLE REGION, NC
The five-year pump-out requirement has resulted in better maintained systems and the identification of system malfunctions that would otherwise go undetected. As a result of these measures, fewer owners are facing costly major repairs or system replacements.
Through its program, Fairfax County now better understands and manages its many onsite systems even in light of a fast-growing population.
HAMILTON COUNTY, OHIO
THE SEA RANCH, CALIFORNIA
THE SEA RANCH, CALIFORNIA
Studies conducted in 2000 and 2001 found a 54% improvement in suspended solids, a 36% improvement in biochemical oxygen demand, and a 60% improvement in fecal coliform over baseline data collected five years earlier.
In addition, mechanical system malfunctions dropped from a high of 44% to a consistent and predictable rate of around 18%. Nonmechanical system malfunctions were over 23% in 2003 and have currently dropped to 2.6%. Onsite sewage treatment system nuisance complaints dropped from 371 in 2003 to 258 in 2009.
THE SEA RANCH, CALIFORNIA
THE SEA RANCH, CALIFORNIA
THE SEA RANCH, CALIFORNIA
Surface and groundwater monitoring results have found no evidence of groundwater pollution associated with the hundreds of individual systems and two clustered wastewater systems in The Sea Ranch community. System malfunctions, such as the sewage surfacing and groundwater contamination that spurred the creation of the program no longer pose a significant threat due to routine operation, maintenance, and management procedures.