With urban sprawl continuing on it's never ending march many people who used to use a septic system are now connected with municipal sewer services. A great way to re-use the existing septic tank is to convert it to a cistern.
Keys Net has put together a great set of instructions for taking your anaerobic tank and turning it into a cistern.
- Obtain a variance from the Department of Health (if needed). The fee will include an inspection by the Department of Health of the water in the new cistern to assure that it is not contaminated. The chlorine bleach described later will ensure that the water is properly disinfected.
- Have the septic tank pumped out and pressure-cleaned by a certified septic pumping contractor. Most contractors have a pressure washer and fresh water supply on their truck. Ask them to thoroughly clean the inside of the tank and then pump out the wash water.
- Connect the roof gutter downspouts to the tank using 3-inch PVC pipe. Usually it can be connected to a stub of the old fill pipe running from the house. It is a good idea to add a piece of 1⁄8-inch mesh screen between the gutter and the cistern to catch debris flushed from the roof during the beginning of a rainstorm.
- Connect an overflow pipe to the cistern tank. This is usually a couple of 3-inch PVC 90-degree elbows, which allow water to flow out of the cistern if it overflows. Install a grate or screen to prevent access by rodents and mosquitoes. It is also a good idea to add a splash basin or gravel field to reduce erosion and guide the overflow where you want it to go.
Find out more and get the rest of the instructions at Keys Net.