The key to maintaining proper wastewater treatment and protecting water quality is to provide adequate maintenance of the wastewater treatment system. Whether it is an onsite wastewater systems (septic tank) or decentralized community wastewater treatment plant, a common problem in regard to water quality contamination for both surface and ground water is the lack of ongoing and adequate maintenance of the system by the user or owner.
Ongoing maintenance includes regular pump out and removal of solids in the septic tank every 3 to 5 years. Additionally, the lateral field or drain field must be adequately sized to spread out the liquid from the household and must be kept free of large trees, vegetated in grass and shrubs and prevented from compaction by vehicles and traffic. Over 80% of the treatment of household wastewater in a conventional septic system is done by bacteria and microorganisms in the soil of the lateral field.
An additional challenge for rural wastewater treatment is the karst geology (rocky, shallow soils) of the Beaver Lake watershed. The soil conditions are often not compatible to the use of conventional onsite septic systems for household wastewater treatment. As our population increases, failing onsite systems not only cause problems for surface waters, i.e. lakes and streams, but also groundwater and wells can be at risk of contamination.
As new technologies are being accepted and proven for wastewater treatment, new and replacement septic systems are seeing a shift from the conventional, gravity-fed tank and drain field to more advanced treatment systems. The advanced treatment systems contain, in addition to a septic tank, a pretreatment chamber with aeration to promote digestion of wastewater by bacteria. Pretreated wastewater is then pumped into dispersal lines or drip irrigation lines which spread it out in the soil for final treatment. Whether an advanced treatment or a conventional septic system is installed on a particular property depends upon the soils at that site. The downside to advanced treatment systems, besides additional maintenance requirements, is costs, which is usually double or triple the cost of conventional systems.