Septic System, Driveway and Grading Plan Designs
At Mace Consulting Engineers, the desires of the client are implemented to the greatest extent possible, always keeping in mind the economics of the project in concert with sound engineering practices. The construction of a new home can be an exciting time. It can also be a very stressful time. Professionals with a proven track record best handle the myriad of rules and regulations, which need to be addressed. Residential site plans need to take into consideration many different aspects of planning. These include...
- Proposed House Location
- Size
- Design
- Layout
- Driveway Location and Slope
- Septic System Location
Prior to receiving a septic system permit the client will need to demonstrate that the lot in question will support an individual subsurface sewage disposal system. This is accomplished by excavating a minimum of two soil profile pits, to a depth of ten feet, to analyze the soil. Samples of the soil are taken and the permeability of the soil is tested in our laboratory as required by state codes.
After a field survey is completed, a base map can be drafted which will include topographic conditions in and around the site, such as neighboring houses, wells, septic systems, etc. At this point the engineers have the necessary information to begin designing the septic system and driveway plans. Grading plans are incorporated into the septic system and driveway plans to ensure proper storm water routing and/or management.
The location of the soil profile pits is critical, due to the fact that the septic system must be built within fifteen feet of them. Gravity flow from the house to the septic system disposal bed is typically the most inexpensive system to build, so it is important to site the house several feet vertically above the soil profile pit areas. There are also a number of isolation distances, which must be respected in relation to the septic system location. Mace Consulting Engineers produces the plans, applications, letters, and supporting documents for the appropriate reviewing agencies approval. The submission of these documents is coordinated entirely by MCE. Driveway and Grading plans are fairly self descriptive. While not much needs to be discussed relative to them they are nonetheless an important component of the residential lot design.
Septic System Design
The purpose of a septic system is to provide treatment and disposal of sanitary sewage. The septic system disposal bed size is based on usage and soil permeability. The typical in-ground or mounded septic system provides two forms of treatment. The primary treatment process occurs in the septic tank where solids settle out from liquids and are treated by an anaerobic process, which partially digests the organic matter. The secondary treatment process occurs in the upper four feet of the disposal bed where pollutants are removed from the septic tank effluent by physical interactions between the gravel filter material and the soil. Finally, the lower four feet of soil within the septic system bed is used to promote downward or lateral movement of the treated wastewater away from the area of the septic system disposal bed.
Advanced technology is being applied to situations where septic system malfunctions are occurring. In years past, homes and septic systems were located in areas, which did not promote effective treatment and/or disposal of sewage effluent as per current required standards. As these older systems require replacement or alteration we find increasingly more difficult challenges in design parameters. In extreme cases of malfunction where the possibility of ground water contamination is a concern, the administrative authorities have been requiring greater degrees of treatment. MCE has been incorporating Peat Moss Technology in our designs for these ‘worst case’ malfunctions. This technology is approved by the DEP for use in alterations due to system malfunction. Sphagnum Peat Moss has properties, which can treat septic system effluent to a much higher degree than the typical gravel and soil disposal bed. While the administrative authorities have approved these types of systems they do require a much more intensive review, installation and maintenance process.
For simplicity, we have broken down the septic system designs into three basic categories:
Septic In-Ground Systems
In-ground systems are entirely below existing ground levels. They can be gravity fed or pressure dosed and are generally the most inexpensive and aesthetically pleasing. In-ground Septic System Detail.
Septic Mounded Systems
Mounded systems are above ground and are most often pressure dosed. They are typically constructed when a soil-limiting zone is encountered at a shallow depth from existing ground levels. They are generally considered less pleasing to the eye and can be more expensive to construct. Mounded Septic System Detail.
Peat Moss Technology Systems
Peat moss systems are allowed to be constructed when a system is in a state of malfunction. They can be in-ground or mounded systems. They are comparable in price to a mounded system and can be used to lower the height of a mounded system. While the cost to construct these systems is comparable to a mounded system, the design, permitting, and maintenance protocols are much more stringent.
Mace Consulting Engineers
985 Belvidere Road • Phillipsburg, NJ 08865
(908) 454-9500 • Fax (908) 454-2262
