WSNTG Annual Conference September 2006 Water Services National Training Group 10 th Annual Conference 7 th September 2006

WSNTG Annual Conference September 2006

Water Services National Training Group

10th Annual Conference

7th September 2006


Alternative Wastewater Systems - Technical Aspects: S.T.E.D.S.

Geoff Salthouse

Project Engineer

Orenco Systems®, Inc. (U.S.)


Presentation Outline

Introduction Brief History of the Technology Orenco® Effluent Sewer Overview Secondary Treatment Overview Collection and Treatment System

Costs


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


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



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.






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


Effluent vs Gravity Sewer


Effluent Sewers in the U.S.


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 ...


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

Effluent Sewer Overview


Septic Tank Effluent Pumping Septic Tank Effluent Gravity

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


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



Component compatibility with an engineered package containing– Pump vault– High-head effluent pump– Biotube® filter cartridge– Float assembly– Discharge assembly– Splice box



Effluent Pump Non-corroding stainless steel Designed for wastewater Lightweight; under 14 kg Long life; 20 to 30 years



VeriComm allows for 24/7 supervision with remote monitoring

Operation and maintenanceis simplified

Standard panel without telemetry is available



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

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

Effluent Sewer Advantages


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


CharacteristicsOrenco

Effluent SewerConventionalGravity Sewer

Grinder /Vacuum Sewer

low strength(liquids only)

full strength(liquids & solids)

full strength(slurry)

BOD5 100 - 150 mg/L 200 - 450 mg/L 300 - 450 mg/L

TSS 20 - 40 mg/L 200 - 450 mg/L 300 - 450 mg/L

Fat, Oil, & Grease 10 - 20 mg/L 50 - 150 mg/L 60 - 160 mg/L

Small and Decentralized Wastewater Management Systems, Crites & Tchobanoglous, 1998.

Quality of Treatment


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


AdvanTex® Treatment

Packed bed filter Engineered textile

material Appropriate tankage and

timed dosing Complete, pre-

manufactured package


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


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

Orenco STEP Cost


On-Lot O&M Costs

STEP systems– Annual power consumption: €10– Inspection and monitoring: €25 per 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)


Collection System

Typical Installed Costs

Item CostCollection pipe (50 - 150 mm) €15 - €40 per metreAir release assembly €250 - €500 eachPigging port assembly €400± eachCleanout assembly €120± eachCrossings (stream/RR) €400± per metre


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


Initial vs. Deferred Costs


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

Documents

WSNTG Annual Conference September 2006 Water Services National Training Group 10 th Annual Conference 7 th September 2006