The Three Lakes Council has a Water Clarity Committee dedicated to maintaining and improving the quality of our lake water. When you live by a lake, it is essential to pump your septic system every two to three years to prevent it from contaminating the lake's delicate ecosystem. The proximity to groundwater and the risk of polluting the lake mean that you should not wait for the standard three-to-five-year interval recommended for other areas.

Preventing nutrient pollution. A properly working septic system filters wastewater through a drainfield, where soil and bacteria break down contaminants. A failing system, however, can release excess nutrients like phosphorus and nitrogen into the surrounding soil. Near a lake, these nutrients can travel through the groundwater and cause harmful algae blooms and excessive weed growth.

Navigating high groundwater. The higher groundwater tables near lakes can negatively affect a septic system. If the tank's contents are not regularly pumped, a high groundwater table can flood the drainfield and cause the system to back up into your home or contaminate the surrounding area.

Protecting public and wildlife health. A failing septic system can introduce pathogens such as E. coli, bacteria, and viruses into the lake. This contaminates the water, making it unsafe for swimming and harming aquatic life. Untreated wastewater is a direct public health hazard.

Avoiding drain-field failure. When the septic tank becomes too full of solid sludge, it can overflow into the drainfield. This clogs the pipes and prevents the soil from filtering wastewater effectively, leading to system failure. Near a lake, the soil may already have a high water table or be saturated during high-water periods, making it more vulnerable to drain-ffield failure.

Wastewater study 4/30/23
Why? What's the context? In a word: phosphorus. A recent scientific study of our lake concluded that improperly or poorly maintained septic systems (not regularly pumped) add phosphorus to the lake water, which is chiefly responsible for the unwanted growth of algae and weeds. For more info, follow this link: 

​Septic Systems - Three Lakes Council

​The water quality of Lewisboro's lakes has long been a concern and a discussion topic. With New York City's water supply impacted, the City is a stakeholder and property owner right here in Town among our lakes. This makes grant funding available from the City Department of Environmental

 Town of Lewisboro Website:
Cleaning Up Our Lakes: Septics & Sewers1:1 Coaching