Onsite Wastewater Treatment Systems (OWTS)

Onsite Wastewater Treatment Systems (OWTS) Program

The OWTS Program protects people and the environment by making sure sewage and greywater are handled safely. We:

• Review and issue permits for on-site sewage systems
• Regulate greywater systems
• Oversee septage haulers (pump/transport companies)

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Building or Repairing a Septic System (Conventional)

Permit Steps (At-a-Glance)

1. Apply: Submit application, fee, a to-scale plot plan, and a simple site map.
2. Site evaluation & testing: Test trenches and percolation tests (by a licensed professional/REHS) as required.
3. Review & decision: We review submittals and field conditions; if approved, a permit is issued.
4. Build with inspections: Schedule required inspections at each stage (see below).

Required Inspections

• Site & soil profile (before permit issuance)
• Open trench (before placing rock/pipe)
• Final (tank, leach lines, distribution)

Key Site Basics

• Adequate soil and acceptable percolation (typ. 5–60 min/in)
• Vertical separation ≥ 5 ft from trench bottom to groundwater/bedrock
• Reserve area equal to 100% of the leach field
• Slope under 30%
• Example setbacks: wells 100 ft; buildings 5 ft (tank) / 8 ft (leach lines)

Operation & Maintenance (O&M)

• Do not flush wipes/solids or pour grease/harsh chemicals down drains
• Protect the leach field (no parking, paving, or heavy landscaping on top)
• Pump the septic tank every 5–7 years (more often with heavy use)