Decentralized Wastewater Workshop Greenville, South Carolina July 30, 2009 Land Disposal of Treated Wastewater Treatment & Disposal Options Overview Primary Treatment Conventional Sand Line Drain Field Trench / Solids Separation Disposal Disposal Secondary LPP Disposal Sand Mound Treatment Disposal Tertiary Drip Spray Re-Use Irrigation Irrigation Treatment (Purple Pipe) Disposal Disposal 2 Secondary Treatment Treatment Method Options Attached Growth Suspended Growth • Orenco Recirculating Packed- • Extended-Air Activated Bed Media Filters Sludge Plants • Aqueonics Multi-Stage • ATU’s (aerobic treatment Trickling Filters units) • Aquapoint Bioclere/Lotus • SBR’s (sequencing batch Modified Trickling Filters reactors) • Puraflo Peat Fiber Biofilters • MBBR’s (moving bed • Recirculating Sand Filters biological reactors) 3 Tertiary Treatment Treatment Method Options Effluent Polishing • Disc Filters • MBR’s (membrane biological reactors) • Constructed Wetlands • Disinfection 4 Secondary Treatment Options Orenco AdVantex Recirculating Packed-Bed Media Filter 5 Secondary Treatment Options Aqueonics Multi-Stage Trickling Filter 6 Secondary Treatment Options Aquapoint Bioclere Modified Trickling Filter 7 Secondary Treatment Options Puraflo Peat Fiber Biofilter 8 Secondary Treatment Options Recirculating Sand Filter (RSF) 9 Secondary Treatment Options Extended-Air Activated Sludge Plant 10 Secondary Treatment Options Clearstream ATU 11 Secondary Treatment Options SBR 12 Secondary Treatment Options Puraflo PuraMax MBBR 13 How to Select the Right System Decision Process Overview • Define Wastewater Flow Rate and Characteristics • Identify Potential On-Site & Off-Site Options • Conduct Preliminary Site Reconnaissance Feasibility • Perform Feasibility & Cost Evaluation of Options of Options • Identify System Ownership and O&M Provider • Conduct Pre-Design Conference with DHEC • Conduct Detailed Site Investigation • Identify & Quantify Suitable Disposal Area(s) Site • Determine Long-Term Acceptance/Loading Rate (LTAR) Suitability • Obtain DHEC Concurrence with Findings • Determine Feasible Disposal Method(s) • Determine Required Treatment Method(s) • Perform Cost Evaluation & Select System System • Submit Preliminary Engineering Report for DHEC Approval Selection 14 Individual Lot Conventional Drain Field System Summary Std. Septic Tank & Stone Drain Tile Field Drain field requires cleared land w/ < 10% slope. 3,000 sq ft active drain field + 50% repair area Approx. Unit Cost = $4,000 - $5,000 per lot. 15 Individual Lot Drip Irrigation System Schematic 16 Individual Lot Drip Irrigation System Summary Std. Septic Tank + Secondary & Tertiary Treatment. Subsurface drip field requires un-cleared land w/ < 33% slope. 2,000 sq ft drip field + no repair area. Approx. Unit Cost = $25,000 - $28,000 per lot. Requires 110-volt power supply + telephone line. Requires routine maintenance @ approx. $600/yr. 17 Individual Lot Drip Irrigation System Cost (City of Austin, TX) Estimated drip irrigation system costs, installed, including controls and alarm, (not including pretreatment $15,000 unit(s)), Energy costs (using 0.193 KWH/day energy use), $0.47/month O&M, with a maintenance contract of $540/year (est. 18 hrs. @ $15/hour * 2.0, including taxes, overhead, and $45/month profit), Equipment repair/replacement costs, estimated at $4.17/month $50/year, 20-year NPW (not including design & permitting costs), $20,934.68 18 Individual Lot Repair Solution Camden County, NC AdVantex Pre-Treatment & Sand Mound Disposal over Sand Line Trench 19 Communal Drain Field System Overview 100-Lot Subdivision, Avg. 3-BR, in Upstate Primary Treatment 0.4 GPD/Sq Ft LTAR Requires 6.9 acres of Active Drain Field plus additional 3.4 acres for 50% Repair Area HOA Ownership (excluding Collection System) Permitting by DHEC-Bureau of Environmental Health (up to 50,000 GPD +/-) Approx. Unit Cost = $5,000 - $6,000 per lot 20 Communal Drain Field Cottageville Elem School 21 Communal Drip Irrigation System Overview 100-Lot Subdivision, Avg. 3-BR, in Upstate Primary & AdVantex Secondary Treatment 0.2 GPD/Sq Ft LTAR Requires 4.1 acres of Subsurface Drip Field & No Repair Area Requires Routine O&M Requires Utility Ownership Permitting by DHEC-Bureau of Water Approx. Unit Cost = $18,000 - $20,000 per lot 22 Ralph Chandler Middle School Surface-Drip Irrigation System Decision Process 23 School Surface-Drip Irrigation System Overview New Ralph Chandler Middle School at Fork Shoals - Orenco Recirculating Media Filter Treatment - 6-Acre GeoFlow Surface-Drip Irrigation Disposal - 0.1 – 0.2 GPD/Sq Ft LTAR - 250,000 Gal (2 weeks) Treated Effluent Storage - 15,900 GPD Design Flow - 4 Groundwater Monitoring Wells - $1.6 Million Construction Cost - Contract Operator – All Seasons Environmental Laboratories - Orenco Vendor Oversight Operations Contract - AQWA 24 School Surface-Drip Irrigation EQ Tank, Recirc Pumps, & Treated Effluent Storage 25 School Surface-Drip Irrigation AdVantex Treatment Pods 26 School Surface-Drip Irrigation Irrigation Pumps & Disc Filter 27 School Surface-Drip Irrigation Surface-Drip Irrigation Field 28 Wrap-Up …. What Makes a Decentralized System Successful? Suitability of Site & Sustainable Loading Rate. Proper Application of Treatment & Disposal Methods Selected. Good Design. Good Installation. Good O&M. Thanks for your attention …. 29
"Subdivision Lot Contract"