Here are some links to regulators, industry professionals and organizations which can provide additional information.

Homeowner’s Septic System Guide from NOWRA

EPA Homeowner's Guide to Septic Systems

Information for Septic System Owner’s – Good info from King County, WA

Clark County Environmental Health Department

Washington Department of Health

Washington State Department of Ecology

WOSSA – Washington Onsite Sewage Association

NOWRA – National Onsite Wastewater Recycling Association

Enviro-Flo, INC – Manufacture of quality on-site wastewater products

ORENCO – Manufacture of high quality on-site wastewater products

GLENDON – Proprietor of the Glendon® Biofilter Technology