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Explore the history, design, and benefits of effluent sewers for decentralized wastewater treatment. Learn about Orenco® Systems' innovative solutions and their cost-effective, low-maintenance approach to wastewater management.
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Water Services National Training Group 10th Annual Conference 7th September 2006 WSNTG Annual Conference September 2006
Alternative Wastewater Systems - Technical Aspects: S.T.E.D.S. Geoff Salthouse Project Engineer Orenco Systems®, Inc. (U.S.) WSNTG Annual Conference September 2006
Presentation Outline • Introduction • Brief History of the Technology • Orenco® Effluent Sewer Overview • Secondary Treatment Overview • Collection and Treatment System Costs WSNTG Annual Conference September 2006
Orenco Systems®, Inc. • Established in 1981 • About 300 Employees • Designers and manufacturers of decentralized wastewater technologies for individual properties and small communities • Injection-molded fiberglass tanks • Effluent pumping and filtration systems • Community collection systems • Advanced treatment systems • Monitoring and control devices WSNTG Annual Conference September 2006
History of Effluent Sewers “If there is not enough fall to give a self-cleaning velocity in the main drain, it will sometimes be possible to put in a septic tank at the head of it. The effluent from a septic tank, being free from any solids capable of choking a drain, may safely be laid with a merely nominal fall.” -- A. J. MartinThe Work of the Sanitary Engineer London, 1935 WSNTG Annual Conference September 2006
History of Effluent Sewers • 1960: Zambia* • 1962: Australia** • STED (septic tank effluent disposal) systems developed • Simple oxidation lagoons provide secondary treatment • Reuse developed, using small extended aeration plants • Over 110,000 people in S. Australia served by STEDs • 1964: Nigeria* * The Design of Small Bore Sewer Systems, 1985.** EPA Alternative Wastewater Collection Systems Manual, October 1991. WSNTG Annual Conference September 2006
History of Effluent Sewers WSNTG Annual Conference September 2006
History of Effluent Sewers WSNTG Annual Conference September 2006
What are Effluent Sewers? • An alternative to conventional gravity sewer • The collection and transportation of wastewater to a treatment site • Usually associated with decentralized treatment • Can be integrated into an existing conventional gravity sewer WSNTG Annual Conference September 2006
Effluent vs Gravity Sewer WSNTG Annual Conference September 2006
Effluent Sewers in the U.S. WSNTG Annual Conference September 2006
Effluent Sewer Supported • In 1997, the USEPA submitted a Response to Congress on Use of Decentralized Wastewater Treatment Systems • An excerpt from the EPA’s Executive Summary: Adequately managed decentralized wastewater systems are a cost-effective and long-term option for meeting public health and water quality goals ... WSNTG Annual Conference September 2006
Effluent Sewer Overview WSNTG Annual Conference September 2006
Effluent Sewer Overview • Shallow burial depth • Laid to contour of land • No minimum velocities • No oversized designs • Low operation and maintenance costs • Odor control necessary in certain applications WSNTG Annual Conference September 2006
Orenco Effluent Sewers • Septic Tank Effluent Pumping • Septic Tank Effluent Gravity WSNTG Annual Conference September 2006
Orenco Effluent Sewers • Orenco Effluent Sewers • 25 years of documented system performance in Glide, Oregon; 900 connections • Regional examples: • North: SW Barry County, Michigan; 1000+ Strathcona, Alberta; 300 • West: Missoula, Montana; 2500 Penn Valley, California; 240 • South: Ariton, Alabama; 340 WSNTG Annual Conference September 2006
Orenco Effluent Sewers • Primary treatment in interceptor tanks • 4000-litre tank per residence • 70% removal of fats, oils, and greases • 24-hour emergency storage • 12-year pumpout with 95% confidence • Abuses stay in interceptor tank • Chemical sources easier to identify WSNTG Annual Conference September 2006
Orenco Effluent Sewers • Component compatibility with an engineered package containing • Pump vault • High-head effluent pump • Biotube® filter cartridge • Float assembly • Discharge assembly • Splice box WSNTG Annual Conference September 2006
Orenco Effluent Sewers Effluent Pump • Non-corroding stainless steel • Designed for wastewater • Lightweight; under 14 kg • Long life; 20 to 30 years WSNTG Annual Conference September 2006
Orenco Effluent Sewers • VeriComm allows for 24/7 supervision with remote monitoring • Operation and maintenanceis simplified • Standard panel without telemetry is available WSNTG Annual Conference September 2006
Effluent Sewer Advantages • Flexible in design • Adaptable to varying site conditions • Allows for phased buildout • Can be integrated into existing sewer infrastructure • Design includes storage/reserve in the event of power outages or need to repair mainline break • Low-impact construction • Minimal disruption to community WSNTG Annual Conference September 2006
Effluent Sewer Advantages • Cost-effectiveness • Low initial costs • Deferred capital costs • No manholes • No lift stations • Low operating costs • Low maintenance costs • Low and gradual repair/replacement costs WSNTG Annual Conference September 2006
Quality of Treatment • The ONLY collection technology that provides treatment • 70 to 90% reduction in waste strength • Collection and treatment technology integration • Reduced hydraulic and biological loading to treatment facility WSNTG Annual Conference September 2006
Quality of Treatment Small and Decentralized Wastewater Management Systems, Crites & Tchobanoglous, 1998. WSNTG Annual Conference September 2006
Secondary Treatment Packed Bed Filter - Attached Growth Process • Highly stable, reliable • Uses fixed film media • Operates in an unsaturated condition (not submerged) • Employs intermittent dosing • Uses filtration and biological/chemical reduction • Produces a net reduction in cellular mass due to endogenous respiration • Little or no sloughing • Minimal solids accumulation WSNTG Annual Conference September 2006
AdvanTex® Treatment • Packed bed filter • Engineered textile material • Appropriate tankage and timed dosing • Complete, pre-manufactured package WSNTG Annual Conference September 2006
Attached Growth • Aerobic microbes attach and grow on media • Wastewater flows across a zoogleal film created by microbes • Microbes extract and digest soluble organic matter from the wastewater WSNTG Annual Conference September 2006
Orenco STEP Cost Installed Cost: €2700 - €3500 • Building sewer • Interceptor tank, risers and lids • ProSTEP™ pump package • Control panel • Electrical conduit & wire • Electrical power to controls • Service line WSNTG Annual Conference September 2006
On-Lot O&M Costs • STEP systems • Annual power consumption: €10 • Inspection and monitoring: €25per year • Inspections conducted: every other year • STEG systems • Annual power consumption: €0 • Inspection and monitoring: €16 per year • Inspections conducted: every other year • Tank pumpout (10 to 12 year intervals) WSNTG Annual Conference September 2006
Collection System Typical Installed Costs WSNTG Annual Conference September 2006
Treatment System Costs • Treatment system installation • €0.83 to €2.10 per treated cubic metre • Includes engineering, permitting, and construction • O&M costs • Approximately €10/month/cubic metre WSNTG Annual Conference September 2006
Initial vs. Deferred Costs WSNTG Annual Conference September 2006
Summary • Effluent Sewers are: • Affordable • Low Installation, Operating, and Maintenance Costs • Effective • Provide Consistent Primary Treatment • Reduce Treatment Plant Size • Proven • Hundreds of Installed Systems • Versatile • Designed for Specific Applications WSNTG Annual Conference September 2006