Septic tanks and lake nutrients
Ground water flows from the southeast to the northwest in our watershed. This photo shows the number of septic tanks upstream from American Lake.
The effluent from septic tanks flows across drain fields. It coats the rocks which provide a surface area for naturally occuring bacteria to break it down into its chemical components. The nitrogen and phosphorous from these drain fields can flow through the groundwater and act as liquid fertilizer for plants, algae and cyanobacteria living in the lake.
More details
Pierce County built its first sewer system in 1981 and created Utility Local Improvement Districts (ULIDs) to protect public health and groundwater resources. Many lakeshore residents were able to abandon their septic tanks and hook up to the sewer lines at that time. Lakewood incorporated in 1996 and began their own sewer construction in the early 2000s. The Tillicum neighborhood was partially supplied with sewers, but not all residents have been able to afford the hook-up fees. There are also some design requirements that went into effect after development, as in the Eagle Crest neighborhood, so that many septic tanks are still functioning.
One lake study in 1997 concluded that the number of drain fields and septic tanks upstream of American Lake was a significant contributor to nutrient loads in the lake water.
The City of Lakewood, in concert with Pierce County Conservation District, used volunteer citizen scientists to collect water samples. These samples were measured for any changes in nitrogen and phosphorous levels in lake water. After 15 years, since no significant changes were noted, the City discontinued payment for lab tests. There are no current records of present nitrogen and phosphorous levels.
Contact
I'm always looking for new and exciting opportunities. Let's connect.
123-456-7890