Progress / Science

On-Site Septic Drainfield Innovations Around Vermont’s Lakes and Ponds

For a tiny state, Vermont has a lot of lakes and ponds, over 800 total. In the 1950s and 60s, many seasonal cottages were constructed on very small lots to serve a limited occupation and use. Today, there is pressure to use these cottages more frequently as rentals or to convert them to year-round residences. Many of these properties were developed before environmental regulations were in place and when little was known about soils and wastewater treatment. In fact, some of the earlier systems were designed to be partly in the groundwater table to facilitate the movement of water back into the environment. We now understand that a few feet of unsaturated soils are needed to treat the wastewater before entering groundwater. This will reduce the number of pathogens and nutrients that can impact wells, lakes and ponds, and swimming areas.

Prior to purchasing a property on a lake or pond, know the septic limitations. The property may not be able to be converted into a full season home without a substantial investment.  If you are thinking of renting a lakeside property, consider the risks and costs associated with repairing a failed wastewater system. Educate guests and renters on the use of a septic system – many have never used an on-site septic system and do not know what should not be flushed down the drain or understand the importance of water conservation.

If an owner wants to add a bedroom or upgrade their existing wastewater system, they may find themselves in a situation where they cannot expand. Waivers may be needed for replacement wastewater systems due to pre-existing site conditions. What is a homeowner to do, when their property cannot sustain a complying wastewater drainfield? Here are some innovative solutions to consider:

  1. Install a composting toilet and low flow fixtures. While this solution won’t solve treating the graywater flows from sinks and showers, it will greatly reduce the volume, pathogen, and nutrient load to the system. This can improve water quality and extend the life of the drainfield.
  2. Work with your neighbors. Consider sharing the septic tank and/or drainfield to reduce the area needed for both components. This may require easements and agreements, but is a very feasible solution. It can be as simple as connecting two cottages or it can be a community system to serve multiple properties.
  3. Consider drip distribution. This is a newer technology in Vermont and other parts of the country, but it has some great benefits including providing superior pathogen and nutrient removal within the existing landscape. The ½ inch tubing can be located near trees and other landscape obstacles and terrain with the added benefit of irrigation.

Finally, remember to perform regular maintenance tasks on your septic system. If you have an effluent filter at the outlet of your septic tank, clean it every 6 months. If you don’t have one, consider retrofitting your tank to install one. If you have a septic tank, have the tank pumped every 2–3 years.

Mary Clark is an Environmental Program Manager at the Vermont Department of Environmental Conservation with more than 40 years of experience working in the onsite wastewater industry. She is also the President of the State Onsite Regulators Association (SORA).