STEP/Liquid Only Sewer
STEP Systems - a Better Collections System aPproach
STEP (Septic Tank with Effluent Pump) also known as Liquid-Only Sewer collections systems are an economical, low-impact, long-term solution to collecting and delivering wastewater to a treatment facility.
Some of the benefits and features in the technical papers and project profiles linked at the bottom of the page include:
Watertight collection, with no need for manholes or expensive lift stations
Shallowly buried, small-diameter sewer lines, quickly installed with light equipment
Passive, on-lot primary treatment
Reduced size, complexity, and cost of the wastewater treatment system
A minimum of 24-hour emergency storage in watertight, on-lot tanks (with normal, daily flow)
Low Operations & Maintenance costs
Lower upfront cost
Cost deferred until buildout
Non-mandatory hookups
STEP collections systems can significantly reduce the need to dig up roads, sidewalks, and otherwise disturb traffic flow and landscapes.
Courtesy of Orenco http://www.orenco.com/systems/wastewater_collection.cfm
There are two primary STEP configurations that AQWA uses in the Carolinas and Virginia. AQWA STEP and Biotube ProPak Pump Packages installed in precast tanks. A third option to consider is the Orenco Prelos System.
1) AQWA STEP Package
This STEP package includes all of the contents of an Orenco® Biotube® ProPak™ Pump Package pre-installed into an Roth Manufacturing 1000 gallon poly tank. AQWA finishes out the STEP packages with tank adapters, lids and risers cut to your communities specifications for consistently watertight installations.
Roth Tanks are the best plastic tanks on the market, lightweight yet incredibly strong and backed by an industry leading warranty. This package makes for an easy install and is lightweight and simple enough for municipal staff, plumbers, or septic installers to handle and install.
All float and pump wires are pulled to the splice box with each cord labeled making control panel hook up very straightforward.
Package includes:
S1 Control Panel (Any Orenco Panel can be specified including Vericomm, telemetry enabled panels)
2) Orenco STEP Packages
Orenco® STEP Packages are complete, integrated pump packages for filtering and pumping effluent from septic tanks or pump tanks. They are designed to filter and pump effluent to either gravity or pressurized discharge points. The patented pump vault technology eliminates the need for separate dosing tanks.
10-, 30-, and 50-gpm (0.6, 1.9, and 3.2 L/sec) versions available
60-Hz operation
PF Series Corrosion-resistant, stainless steel 4-inch (100-mm) turbine effluent pump
Polyethylene and PVC Biotube filter
1/8-inch (3-mm) or 1⁄16-inch (1.5-mm) filter mesh available
14.5 ft2 (1.35 m2) total filter surface area
140 gpm (8.8 L/sec) maximum flow rate
Float switch assembly and float switches included
Internal or external splice box available
Demand-dose, analog timed-dose, or digital timed-dose control panel available
5-year warranty
If there are existing septic tanks or pump tanks to be converted to STEP, the Biotube ProPak includes all of the components you will need to turn any watertight concrete tank into an Orenco STEP system.
Any project specified for AQWA STEP or Orenco STEP includes a complimentary Hydraulic Grade Line (HGL) Analysis conducted by experienced engineers at Orenco.
Warranty Information
The warranties covering the components of these STEP packages are the best in the industry.
The effluent pumps boast a 10 year warranty when purchased as part of a STEP Package. 10 years! When one of these pumps does fail, typically the liquid end of the pump can be purchase for a minimal cost of
10 year warranty - PF Series Septic Tank Effluent Pump
Lifetime Corrosion Warranty, 5 year workmanship/materials warranty + $2500 to pay for costs associated with tank replacement if one does fail under warranty
All other components - 5 year warranty
3) Orenco Prelos
Prelos: Pressurized Liquid-Only Sewer
The Prelos Processor is the core of the Prelos Wastewater Collection System. With the Prelos Processor, we've brought the ease of specifying, installing, operating, and maintaining a liquid-only sewer to a whole new level. Components are included and designed to work together - simply, durably, and efficiently.
High-quality, watertight tank package
Unique “meander” design for superior solids removal and primary treatment
Only liquids are conveyed to the treatment facility
Easy to maintain, with compatible, long-lifespan components
Single riser and lid provide access to all components
Lightweight, easily rebuildable effluent pump can last more than 25 years4
Optional industry-leading, extended 10yr limited pump warranty available
Single line-item that’s easy to specify
ProSTEP Effluent Sewer Brochure from Orenco
Effluent Sewer FAQ (breakdown of collections systems cost comparisons)
20 Year Life Cycle Cost Analysis
Technical papers
Low-Impact Wastewater Collection System Reduces Nutrient Loads in Vero Beach
Wastewater Collection Systems Comparison
Operational Costs of Two Pressure Sewer Technologies (STEP vs Grinder)
Small Community Collections System Construction Costs
Effluent Sewer Environmental Profile and LEED credits
Case Studies
Environmental Science and Engineering Article on Kinglake West, Australia STEP project on page 34
This video is a good intro for the general public to what an effluent sewer is all about and why you'd choose to do one.
Orenco Effluent Sewers are an affordable, environmentally sound, and easy-to-maintain alternative to conventional gravity sewers. Ideal for municipal sewer expansions, new development, septic tank abatement projects, and commercial or residential clusters.