Forms Click Below For Helpful Resources Boulder County, Colorado Onsite Wastewater Treatment System (OWTS) Regulations Common Types of ISFs Do Your Part. Be SepticSmart! SepticSmart Dos and Don’ts for an Advanced Treatment Unit (ATU) A Homeowner’s Guide to Septic Systems Proper Landscaping On and Around Your Septic System SepticSmart Rental Flyer CPOW Soils Evaluation Course Certificate Tests for Drinking Water from Private Wells Verification Procedure