Hi! Welcome to nhperctests.com, a site providing information on perc tests and septic designs complying with New Hampshire Dept. of Environmental Services regulations.


To arrange to have a perc test and septic design for any piece of land in New Hampshire, E-mail: David@electriciansparadise.com


Types of Septic Systems Used in New Hampshire...

Years ago a septic system consisted of an underground cavern built of cedar logs with a plank roof covered with dirt and surrounded by lots of rocks. Alternately, it was made of stones or concrete blocks. The raw sewage was piped from the house directly into this facility, known as a cesspit.

This arrangement had two major disadvantages -- the raw sewage would clog the surrounding dirt interface so that it had to be dug out from time to time. Secondly, by going deep into the ground the groundwater could be contaminated and in thickly populated areas nearby wells would acquire a high bacteria count.

Modern septic systems eliminate both of these drawbacks. Today all small individual septic systems begin with a septic tank. The sewage from the house goes via a gravity flow pipe to the tank where it undergoes anaerobic bacterial action. This type of bacteria exists where there is no continuous supply of oxygen and the bacteria breaks down the waste material into a dark liquid called effluent which is still toxic since it is teeming with live bacteria but which no longer contains solids and so will not clog the dirt interface.

The second stage is some type of leach facility where the effluent undergoes aerobic decomposition. It is broken down by a different kind of bacteria that thrives in a relatively oxygen rich environment. The leach facility is a large usually rectangular structure, usually one foot thick, that is constructed at or below the original grade. In locations where there is a significant springtime high water table or presence of bedrock, fill has to be brought in to raise the elevation. At the leaching site a knoll is created and this is known as a raised bed.

In the 1970's when New Hampshire started regulating subsurface waste disposal, all leach beds were of the pipe and stone variety -- a network of perforated 4" PVC pipe set in uniformly sized washed stone.

Eventually the chamber system emerged and was approved for use by NH DES. This consists of an array of plastic or concrete half shells placed with the open side down on a bed of sand. This type of system worked well, especially since the State allowed a 60% size reduction which meant less dedicated land and vastly less fill for raised systems.

In recent years a third generation of leach facility structures has become available. These plastic and fabric units are designed with an inner structure that facilitates aerobic digestion and a cover that promotes absorbsion by the surrounding soil.

The good news is that the State allows a further area reduction when these products are used which helps keep the cost down and makes it easier to meet setbacks on problem sites.

I have drawn up many state approved designs using all these systems. At present I am using Enviroseptics manufactured by Presby Environmental of Sugar Hill, NH.

This site is created and conducted By David Herres, NH Septic Designer License 00512. NH Septic Installer License 01249, NH Master Electrician License #11335M

To arrange to have a perc test and septic design for any piece of land in New Hampshire, E-mail: electriciansparadise@hughes.net


HOME