STATEMENT OF PROBLEM AND SPECIAL INFORMATION FOR PRIVATE SEWAGE SYSTEMS (ON-SITE SEWAGE DISPOSAL)
In 1955, with only a degree in biology and chemistry and having taken the exam for sanitarian for the state of Pennsylvania, the author achieved an extremely high grade and was appointed to the position of a field practitioner in Montgomery County, Pennsylvania. At that time, a vast number of houses were being built very quickly, on small pieces of land, sometimes only 10,000 ft2, and having to use well water and septic tank systems to take care of the water and sewage disposal needs of the family that had been reared in most cases in the City of Philadelphia. Mortgages were easily obtained by using either the Veterans Administration program or the Federal Housing Authority program. In either case, the well and the sewage system had to be approved by the county health department which was an arm of the state. Many times, the sanitarian was called out to evaluate several septic tank systems before they were covered and the time allowed was very brief. This led to a quick visual look at the drainage field or seepage pit and almost universal approval.
The author’s training initially was to go out into the field with a practicing sanitarian and squat down beside a hole and be shown that there were 3 feet of shale, and therefore, a seepage pit could be used after the septic tank for disposal of the effluent instead of a tile field system. Tile field systems were also a problem because, although it was required that a professional engineer sign off on a percolation test for a tile field system, they were never conducted by the health department personnel or ever verified. It was only 7 months later during a 9-week, 40-hour-a-week training program conducted by the US Public Health Service at the field training center in Pittsburgh, that the author learned how to properly assess land in order to approve tile field systems and utilize seepage pit systems as a last resort. The reason for this story is so the reader will understand that there are a huge number of non-performing on-site sewage disposal systems throughout the country that are outdated and probably have been overflowing illegally into bodies of water for years. The land site of the house is so small typically that in many cases, it is virtually impossible to replace the system.
What happened here was typical in many areas of the country because of a lack of properly trained sanitarians with the skills and ability to approve a new septic tank system. Speed was essential to meet the demands of the construction companies. Typically, the entire project of hundreds of homes was in an area where a single home had existed for the farmer and his/her family.
The land worked well as a farm because the water wells and sewage disposal were on a vast area for the single house. Now this area was converted into all of these new homes, each of which had to have its own well and septic tank system. The effluent load even if the soil was good was well beyond the capacity of the land.
In 2007, it was estimated that 20% of the housing units (over 26 million housing units) in the United States used on-site septic systems to remove domestic wastewater from the homes in areas where municipal or public sewage systems did not exist. This was an increase of over 1.5 million septic systems since 1985 and is still growing. Some 50% of the systems were in rural areas and 47% of the systems were in suburban areas. (See endnote 1.)
The systems have a typical life expectancy of 20 years. They function by providing a place for solids to settle and then for the effluent to be distributed evenly in the ground. They may be an individual unit or in a cluster. A septic tank system consists of basically:
- 1. A large watertight, underground concrete, fiberglass, or polyethylene/plastic container, with one or more chambers, is used to collect domestic wastewater from the house for primary treatment and holding, for at least a 24-hour period, allowing solids to go to the bottom of the container and floating scum and grease to the top.
- 2. Pipes which come from the house or other structure go to the underground container and from the container are plumbed directly to a header or to an underground distribution box and then to the actual effluent absorption system.
- 3. Install baffles at each of the inlets and outlets of the septic tanks and make them an integral part of the tank. The inlet baffle must extend at least 6 inches above the total liquid depth and at least 1 inch above the inlet sewer pipe. The outlet baffle must extend above the surface of the liquid and depending on the jurisdiction, 40% below the total liquid depth. The system should allow the liquid to flow from the inlet, retain the sewage for 24 hours for settling, prevent floating solids from leaving the tank, and then let it out through the outlet to the header or distribution box.
- 4. The header and the distribution box serve the same purpose to evenly distribute the effluent.
- (In some jurisdictions headers are primarily used and in others distribution boxes.)
- 5. The area of soil is used to absorb the liquid and also may allow it to go into the air through evapotranspiration.
The soil effluent absorption systems may have different configurations based on the on-site soil conditions, however they all have the task of efficiently removing the effluent from the septic tank in such a way that it does not contaminate ground or surface water, come to the surface and contaminate the land, or back up into the house or other structure. Some of the systems include tile leaching fields, mound systems, leaching chambers, recirculating sand filters, low pressure pipe systems, home aerobic treatment systems, etc.
The number of these systems continues to grow because of several factors including: people moving to fringe areas surrounding metropolitan communities; people moving into rural areas; people utilizing waterfront seasonal recreational areas on a year-round basis; and people, especially retirees, seeking remote areas for permanent housing.
There are numerous problems related to on-site systems. The most significant problem is the amount of water that is utilized in the property by the people and then the amount of effluent put into the system for disposal. Other problems include the size of the house lot, the location of the septic tank system and relationship to the well and the house or a neighbor’s system, well, or house, the type and permeability of the soil which is used for drainage of liquid effluent, clogged drain fields, the nature and type of soil testing, the mechanical failure of the system, removal and disposal of solids from the septic tanks, the size of the septic tanks, the age of the system, the presence of bushes and trees in the liquid disposal field, the slope of the land, the site of the system which may not have been laid out properly to start with, the presence of bedrock close to the surface, the concentration of systems in a given area, the functioning of the system in various types of weather conditions especially frequent heavy rains or very heavy snows that last for long periods of time, the maintenance of the system, and the management of decentralized systems.
On-site septic systems should not: cause problems with community or private drinking water supplies by adding nutrients, chemicals, or organic matter; create direct human exposure to fecal material and disease; create harborage, water, or food for insects, rodents, birds and so on; or create odors or aesthetic nuisances for the neighbors or communities.
A Survey of Household Sewage Treatment System Failures in Ohio
Approximate 31% of the household sewage treatment systems in the state of Ohio have some degree of failure. This is an increase from the 23% failure rate reported by the Ohio Department of Health in its 2008 survey of household sewage systems. This is probably not unique and may apply at different levels to all other states. All types of systems were involved starting with the septic tanks and utilizing tile systems, mound systems, sand filters, seepage pits, etc. With almost 194,000 systems failing, this constitutes a very serious environmental and public health hazard and indicates the need for considerably more work to be done in this area to rectify existing problems and to determine how best to deal with situations that seem to be without resolution.