Overview of Clean Water Technologies for the Treatment of Domestic Onsite Wastewater
The following is a guide for people wishing to upgrade their cesspool or septic systems. We call them onsite wastewater treatment systems, since there are many configurations and ways to treat human wastewater. The guide was developed by Peconic Green Growth, Inc, a not-for-profit organization focused on sustainable solutions that integrate natural resource preservation with community enhancements, and funded by a grant from the Long Island Community Foundation.
Why enhance the treatment of onsite wastewater?
To PROTECT our bays and drinking water. Water is the very sustenance of life and a symbol of purification. But local water quality is degrading. Our ground and surface waters need protection. Our aquifers are not only sources of drinking water, but flow horizontally to surface waters, impacting the marine health of our bays. Excess nitrogen compounds are a critical cause of algal blooms, which lower oxygen levels, create toxins, ultimately cause shell fish and fish kills, and decrease biodiversity throughout the whole ecosystem. Contaminants of emerging and critical concern, such as pharmaceuticals and personal care products, need to be treated before being released to ground and surface waters. Water quality is degrading, which will ultimately impact community character and vitality, which are especially relevant for our coastal and tourist economies.
What are the sources of excess nitrogen in our waters?
A major source of excess nitrogen and other contaminants is human waste. Other sources include atmospheric deposition, wildlife, and fertilizer from agriculture, golf courses and homes. While good at protecting groundwater from pathogens, septic systems do not treat many contaminants well enough to protect water quality. Cesspools, which are still common on Long Island, provide NO treatment of any kind: they just disperse polluted water. Properly designed, installed and maintained advanced systems can treat many contaminants well enough to protect water quality.
How can we reduce the amount of nitrogen in our drinking water and in our bays?
This guide describes options for treating onsite wastewater at its source. By the fall of 2016, the Suffolk County Department of Health Services will start to allow the installation of innovative or alternative onsite wastewater treatment systems (“I/A OWTS”). These come in two basic sizes – small: under 1,000 gallons per day (“GPD”) and intermediate: between 1,000 and 30,000 (GPD). A typical house uses 300 GPD. Intermediate-sized options are described in some of our studies (see our Wastewater Studies). Here we will focus on systems more suitable for single-family homes and small commercial uses.
There are three basic approaches:
- Natural Biology: Most commercial and non-proprietary systems take advantage of beneficial bacteria that treat wastewater.
- Waste separation: This is an effective and cost effective way of both controlling nutrient loading and reusing product. This approach tends to require us to change our behavior and needs alternative service models.
- Other alternatives: These are being developed and include ion exchange through direct chemical reactions or alternative pathways in the nitrogen reduction process.
For more information:
What does the Suffolk County Department of Health Services (“SCDHS”) require and regulate?
In Suffolk County, some product options may be limited to a set number of installations because they are still in a pilot approval process. Many systems will be approved by the County for wider application once the initial pilot stage is passed successfully. We suggest you contact the manufacturers of any systems that appeal to you to find out the status of their products. The County will be keeping a list of accepted systems, but there will likely be constant updates during the next couple of years as the program becomes established. The County has applied for funding to help subsidize upgrades by early adaptors, hopefully starting in 2017. The listing of technologies here does not guarantee approval for use by the County. It is an aid for property owners trying to understand options and suitability, either now or in the not-too-distant future. A permit from the County will be required before any system can be installed.
What should you consider when upgrading your system?
When you upgrade, you may be able to reuse portions of your existing system, depending upon what you have and its condition. For more information on older and current systems typically found in Suffolk County, click here.
Generally systems will have similar characteristics based on their system type, but also look for subtle variations and exceptions.
|General Type||Energy Use||Footprint||Maintenance||Power Outage|
|Trickling Filter||Low||Moderate||Easy||Needs generator or bypass|
|Extended aeration||High||Small||Easy||Usually functions|
|Submerged Fixed Film||Moderate to High||Varies||Moderate||Usually functions|
|Membrane Bio-reactor||Moderate to High||Varies||More complex||Needs generator or bypass|
|Soil-based Treatment||Low to Moderate||Varies||Varies||Needs to be designed for gravity flow option|
To learn about specific technologies suitable for single-family onsite wastewater treatment click the following link:
To go directly to the Technology Chart, click here.
Peconic Green Growth advocates widespread upgrades in order to realize water quality improvements that positively impact our bays. We are happy to work with you to encourage home owner associations and communities to upgrade their systems in a wholesale manner. A collective action may help reduce costs, as well as realize environmental goals sooner. Peconic Green Growth, a not-for-profit organization, can also help project designs or act as an owner’s representative for larger projects. If you found this information helpful, please consider donating to Peconic Green Growth.
We would like to thank the cooperation of all the manufacturers and friends who helped edit this website. We welcome further feedback.