Onsite wastewater treatment system repairs Brian Devine Animas
On-site wastewater treatment system repairs Brian Devine Animas River Community Forum June 13 th 2019
Wastewater disposal vs treatment • • • Organic compounds (C-H-O…) Nutrient compounds (N, P…) Fats, oils, grease Suspended solids Pathogens • Treatment is a relatively new invention!
Treatment components • Septic tank (solids, organics, FOG) • Aeration tank (solids, organics***, FOG) • Higher-level treatment (solids, organics***, nitrogen***, FOG) • Soil treatment area (organics, pathogens) • Lagoon (organics? Pathogens? ) • ALL COMPONENTS REQUIRE MAINTENANCE
Wastewater in the San Juan Basin • Until 2003 most systems were designed for disposal or shortterm treatment • 19, 000 permits issued from 1967 to 2019 • Unpermitted pre-1967 systems • Overused, undermaintained, uninspected
Transfer of Title Inspections • Requires third-party inspection of most existing OWTS at time of property sale – Exceptions… recent systems, nonarms-length transactions, ongoing projects • Functional criteria for acceptance – NOT necessary to bring system to 2019 standards – May NOT pose a risk to public health • Repairs must be completed by seller or buyer
Transfer of Title in 2019 • About 195 TRT applications (passed inspections OR agreements for buyers to repair) • 50% increase in repair permit applications – Vast majority are aerator and/or tank replacements • Slight increase in alteration permit applications – Most commonly to accommodate illegally added bedrooms/dwellings • About 85% compliance in Q 1 2019 based on Assessor sale records
• Human-derived e. coli exist in the Animas River • Groundwater generally flows from the valley into the river • Nutrient pollution is associated with algal blooms in the Animas • Nitrate and nitrite levels in Animas Valley wells are generally safe Nitrogen, nitrate/nitrite, mg/L What we know Animas Valley groundwater nitrate/nitrite 4 3, 5 3 2, 5 2 1, 5 1 0, 5 0 0 20 40 60 Well ID 80 100 120
What we don’t know • How much of nutrient pollution in Animas is OWTS-derived? • How much pathogenic pollution in Animas is OWTS-derived? • What benefits to water quality will we see as systems are repaired and replaced? • How will state OWTS regulations look in the future? • What about pharmaceuticals and other persistent pollutants?
- Slides: 8
