350 likes | 366 Vues
Learn how to accurately assess a community's wastewater needs through site evaluations, soil analysis, and treatment options. Determine compliance and potential solutions for non-compliant systems. Explore community-wide options for wastewater management.
E N D
An Accurate Assessment of the SituationDetermining a Community’s Wastewater Needs Nick Haig- University of Minnesota Onsite Sewage Treatment Program haigx003@umn.edu - 612-625-9797
What is a site assessment? • Analyze records • Determine lot size • Locate well • Probe existing system • Conduct soil boring • Match soils • Determine seasonal water table depth • Locate potential drainfield area • Identify treatment options • Check/pump septic tank
Inspection: Results • Certificate of compliance • Certificate of non-compliance • Imminent Threat to Public Health System (ITPHS) • Local policies affect results and homeowner requirements! BUYER BEWARE!
MPCA Unsewered Area Alternative Analysis • Replace failed ISTS with new ISTS. • Decentralized cluster system. • Connect to existing facility. • Connect to a facility, which requires an expansion. • Construct a new wastewater and treatment facility. Note: Solution may be a combination of approaches
Typical assessment: Complying & Non-complying More complete assessment: Complying & ‘Could be’ Complying & ‘Can’t be’ Complying Determining ‘Decentralized’ Feasibility
Typical Assessment Minnesota Lake Comply Don’t Comply
More Complete Assessment Minnesota Lake Could Comply Comply Can’t Comply
Map of parcels Records: Permits Age of systems Maintenance Identify: Likely compliant Spot check Properties to be checked: No records Possible un-permitted work Older than XX years Suspected problems Map of findings Doing the more complete assessment
Septic System Components Source Well Tank Drainfield Treatment in Soil 3 feet Groundwater
Inadequate Vertical Separation Source Well Tank Drainfield Inadequate Treatment Groundwater Pathogens Nutrients 3 feet
Mound System Source Mound Treatment Area Well Tank Pump Treatment in Soil 3 feet Groundwater
What Kind of System is Bad (failing)? • Leaky Tanks • Surfacing to Ground • Inadequate Vertical Separation to Water Table • Direct Discharge
Veseli • Examined the records • Conducted 62 Site Evaluations • Determined the current status of systems • Assessed potential solutions for each property • Evaluated potential cluster sites • Produced map of findings • County cost for time, travel, reporting and some overhead - $76.90/site
Possible Results • “In Compliance”- Meets current Rice Co. Ordinance • “Not In Compliance”- Does not meet current Rice County Ordinance, may need to be upgraded in the future • “Imminent Threat to Public Health System”- ground surface or surface water discharge, sewage backup into dwelling, drywell or cesspool.
Results • 60 Anticipated Site Evaluations • 62 Final Site Evaluations • About 60% of community needed to be inspected because of: • No records • Unpermitted work • Suspected direct discharges • Several homes have been upgraded since 1992 due to Rice County Septic Ordinance property transfer requirements
Veseli- Overall Septic Situation 106 Buildings
Community Options(in no particular order) • Regionalize to Lonsdale (2002 est. = $30,000) • One “decentralized” collection/treatment system for entire community • Several “cluster” collection/treatment systems for entire community • Upgrade all “non-compliant” systems with ISTS and cluster those that cannot fit ISTS
Options (cont.) • Upgrade systems that pose ITPH with ISTS and cluster where necessary • Allow new developments but require them to provide wastewater treatment for existing lots currently not in compliance
Site Evaluation Cost Estimates * $76.90/ Site Evaluation
Beaver Lake Individual “standard” system Individual “other” system or a holding tank Individual holding tank Cluster system
Costs- Beaver Lake • $500 to local ISTS professional • In Kind not counted • $3000-$5000 estimated
More complete assessment • Offers a complete understanding of the current situation • Basis to look at potential solutions • Helps determine appropriate boundaries • Fits with the funding hierarchy changes