Connecticut Department of Environmental Protection Septic Rules, Regulations & Applications

The Department of Environmental Protection (DEP) role in the basic septic design process is to permit and approve subsurface conventional sewage and disposal systems that are designed for daily water flows over 5,000 gallons. This includes sites that process several smaller sewage systems on one “lot” that altogether have a flow over 5,000 gpd (gallons per day).

The DEP also works with community septic systems which involve an underground sewage treatment along with a disposal system. This works with a single system for at least two or more residential facilities, no matter what size the system may be.

The agency that is given authority to regulate the septic system depends on the kind of system, subsurface or over land, and the size of the system. The size is categorized by flow of water: DEP regulates over 5,000 gallons per day, the Department of Public Health has authority over septics from 2,000 to 5,000 gallons per day and the local sanitarian approves and permits any septics which have design flows under 2,000 gallons per day.

What Is Treated In Domestic Waste Water
Septic sewage systems treat waste water that has several pollutants such as chemicals and microorganisms, which may harm both humans and the immediate environment. Treatment includes viruses, protozoa, pathogenic bacteria, nitrogen and phosphorus removal and renovation.

To accomplish this, two methods are employed. First, the on-site waste water renovation system (OWRS) uses a pretreatment facility. Secondly, the subsurface water absorption system (SWAS) takes the OWRS outflow and filters it through subsurface soil until it reaches groundwater.

Basic Design Requirements DEP Septics
1. OWRS must use facilities that have sizes based on approved conservative designs of waste water flows and waste water characteristics.

2. SWAS must have adequate hydraulic ability along with proper hydraulic reserve capacity as required by the Design Standards, to channel the pretreated waste water for a distance that’s far enough to allow the waste water to be renovated into public drinking water standards before it’s accessible to the public.

3. Any inorganic and organic pollutants along with pathogens still in the pretreated waste water are reduced through the soils installed by the SWAS. These soils must contain adequate hydraulic capacity to allow for unsaturated soil at a minimum depth, under the bottom of the leaching SWAS facilities, when there are seasonal periods of higher groundwater, following the Design Standards.

4. Pathogens that have not been eliminated by filtration, inactivation or die-off that remain within the unsaturated region underneath the SWAS, are required to be eliminated through natural methods within the downhill slope of the saturated soils. This should be previous to when the pretreated outflow and the groundwater combine and contact the area of public usage. The amount of time that the waste water takes to travel between the place of disposal and the nearest area of public usage needs to conform to the Design Standards.

5. The abilities of the soil for reducing pathogens shouldn’t be surpassed by the pretreated waste water application rates.

6. The total amount of nitrogen within the renovated and pretreated waste water shouldn’t go over the proper water quality standards, when it’s nearest to the area of public usage, according to the Design Standards.

If you have any questions regarding the interpretation of the above State of Connecticut rules, regulations, and guidelines, or you are interested in working with us on a project, contact us at (860) 354-9346. We look forward to working with you!