Pressure Sewer Systems 3

[655321]

Does anyone out there have experience with pressurized sanitary sewer systems? I'm an engineer for Land Development Consultants, while we have plenty of experience with gravity sewers, we have basically none with these types of systems. It does appears however that a pressure system is the right solution to sewering this project, a residential lake development.

Specifically,
-Is there any good Design Guidance literature out there?
-Are there problems with backflow valves clogging?
-What about cleansing velocity in the pipes before final build out is finished, it could be years before all the homes are online.
-Are there odor problems (from the air release valves)?
-General Maintenance Concerns?

The pump manufacture of the pump system has been much less help then we had hoped.

Thanks in advance for your help.

 

[bimr]

Have you contacted Orenco?

http://www.orenco.com/eps/eps_index.asp

 

[cvg]

http://www.epa.gov/owm/mtb/presewer.pdf

 

[BarryEng]

Try thread181-27567 for info on STEP (septic tank effluent pumping) systems.

Then follow up cvg's suggested web site for more info.

In the website of

http://www.epa.gov,

there is a numerical list of pubs that you can access. I think (I have not got the exact details with me - I'm not at work) the area that you require is EPA625......

They have info on pressurised systems, STEP systems, grinder pump applications etc etc.

Get into the epa website & do a search.

You will be surprised at the qty of info that is available to download. Persevere with the epa web site - it can be difficult to find the exact reference if you have not used it before.

I will try to find the info you require when I go back to work, if you still have not found it.

HAPPY NEW YEAR TO ALL.

 

[BarryEng]

I also meant to mention - there is info on vacuum systems on the epa.gov website, if you require it. Try an internal search of eng-tips (up the top of this page) for more info on these systems. There has been a lot of info posted in recent months on this type of question.

 

[stanleyleecm]

http://www.eone.com/downloads/products/lps_design_manual.pdf

Here is one more for you. We used it a lot around my area (southwest Missouri)

 

[davefitz]

environment one , or eone , grinder pumps seems to be the most flexible system for upgrading a neighborhood that has failing septics and cannot economically supply gravity sewers. Many parts of the country have lakeside communities that had experienced eutrophication from failing septics , and solved the problem by installing the e-one grinder pumps.

Each household would be responsible for the cost of installing the base grinder pump with polypropylene storage tank and electrical connection, and decommisioning their septic/cesspool. As I recall, the base tank + pump is about $1500, plus installation costs. Each house effluent pipe is a plastic 1.25" dia pipe, which is routed to a community pressurized discharge pipe. The community pipe(s) are plastic, wrapped with copper detector tape, routed along the shoulder of the road right of way. The best config is to pump the waste consistently uphill, so that gases formed flow toward the exit, else there would need to be installed vents every 1/4 mile or so. Eventually, the community pipe discharges to a gravity sewer or lift station within 1/2 mile of the first house.

Soundds good on paper, but it reminds me of the scene in the movie "Brazil" where the heating engineer cross connected the air pipe with the pumped sewer pipe.

 

[crawcrow]

you have two basic methods of Low Pressure Sewer on a project like this.

1. Grinder Pump Systems- small fiberglass/poly basins 24" diameter 48 to 60" deep. transports all solids trough force mains to municipal lift station or manhole for treatment. Several manufactures do this e/one is a progressive cavity pump high head low flow but do not handle grit very well) Myers/Hydromatic/Barnes/Zoeller are centrifugal pumps high head flow varies with head pressure more forgiving of grit.
look for installed costs of $3000 a site for new construction

2. STEP systems- septic tank at each home with filtered effluent pump (Orenco, Quanics, Myers, Red Jacket)inside tank or in separate wetwell. This system leaves solids on site in septic tank and pumps gray water (effluent) via small diameter collection pipes to treatment. Effective system when you do not have traditional sewer available and will need to treat onsite. Look for installed costs of $2000 plus septic tank on new costruciton.

 

[655321]

Thanks all for the info. This is a new development - and we're considering the grinder pump system. We're guessing it could take up to 10 years until the project is fully built out, any thoughts on how it would perform during the initial build out conditions, when there is only a handful of houses on what will ultimately be a several hundred home development?

 

[BarryEng]

Go to the EPA USA web site & do a search for grinder pumps. Here are the first few replies.

[1] Manual, Alternative Wastewater Collection Systems (PDF)01-31-2001
EPA/626/i-911024 October 1991 Manual Alternative Wastewater Collection Systems U.S. Environmental Protection Agency Office of Research and Development Center for Environmental Research Information Risk Reduction Engineering Laboratory Cincinnati, Ohio Office Of Water Office of Wastewater Enforcement and Compliance Washington, DC @ Pfinfed on Recycled Paper This document has been reviewed in accordance with the U.S.

http://www.epa.gov/nrmrl/pubs/625191024/625191024front.pdf

(PDF)
[2] No title01-31-2001
CHAPTER 2 Pressure Sewer Systems 2.1 2.1.1 Introduction Background Historically there have been only two choices for the disposal of domestic wastewater: either conventional sewers were used, usually having lift stations as needed within the system, and discharging to municipal treatment works, or septic tanks and drainfields were used. Conventional sewers were generally used in cities and largertowns, and septic tanks and drainfields were more common in rural areas.

http://www.epa.gov/ord/NRMRL/pubs/625191024/625191024ch2.pdf

(PDF)
[3] Wastewater Technology Fact Sheet: Sewers, Pressure
... gravity collection systems because they break down largesolids in the pumping station before they are transported through the collection system.

http://www.epa.gov/OW-OWM.html/mtb/presewer.pdf

(PDF)
[4] Wastewater Primer
"Provides information on Office of Wastewater Management programs."

http://www.epa.gov/npdes/pubs/primer.pdf

(PDF)
[5] On-site Grinding of Residential Construction Debris: The Indiana Grinder Pilot, February 199910-05-2001
Construction Debris

http://www.epa.gov/CDmaterials/pubs/indiana.pdf

(PDF)
[6] Technical Resource Document: Extraction and Beneficiation of Ores and Minerals: Volume 3: Iron
"This document provides information about extraction and beneficiation of iron."

http://www.epa.gov/epaoswer/other/mining/techdocs/iron.pdf

(PDF)
[7] Nonroad Engine Population Estimates, NR - 006c
"The purpose of this memorandum is to document the source of the nonroad engine population values used in EPA's draft NONROAD2004 emission inventory model."

http://www.epa.gov/otaq/models/nonrdmdl/nonrdmdl2004/420p04006.pdf

(PDF)
[8] No title02-14-2001
CHAPTER I Overview of Alternative 1.1 7.7.I Introduction Hisfoty Conveyance Systems In the late 1960’s, the cost of conventional gravity collection systems in rural communities was found to dwarf the cost of treatment and disposal. In response to this condition efforts were initiated throughout the United States to develop low-cost sewerage which could serve the needs of the rural communities which constituted over80 percent ofdemand forcentralized collection and treatment.

http://www.epa.gov/ord/NRMRL/pubs/625191024/625191024ch1.pdf

(PDF)

 

[jrfosterjr]

Be sure and install air release valves at all high points in the system. During the early stages of development, the waste will stand in the pipes for quite a while, allowing gases to build up in the force main. This will effectively reduce the useable capacity of the main and will be the source of many headaches down the road if you leave them out.


Jeff Foster, PE
CE Group, Inc.
Apex, NC