Launch Slideshow

Public Work Utilities Division technician David Bodway with ¬Cousin It,® one of two submersible pumps at a City of Peoria, Ariz., wet well. The pump stations average flow is about 1.1 mgd; peak, 1.8 mgd.

Strangled by disposables, part 2

Strangled by disposables, part 2

  • Public Work Utilities Division technician David Bodway with Cousin It, one of two submersible pumps at a City of Peoria, Ariz., wet well. The pump stations average flow is about 1.1 mgd; peak, 1.8 mgd.

    http://www.pwmag.com/Images/tmp5F82%2Etmp_tcm111-1693141.jpg

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    Public Work Utilities Division technician David Bodway with Cousin It, one of two submersible pumps at a City of Peoria, Ariz., wet well. The pump stations average flow is about 1.1 mgd; peak, 1.8 mgd.

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    City of Peoria Wastewater Collections

    Public Work Utilities Division technician David Bodway with “Cousin It,” one of two submersible pumps at a City of Peoria, Ariz., wet well. The pump station’s average flow is about 1.1 mgd; peak, 1.8 mgd.

  • Unlike a high-speed, low-torque chopper pump, a sewage grinder is a low-speed, high-torque piece of equipment. A 29:1 gear reducer enables this 10-hp JWC Environmental grinder to deliver 45,000 pounds of cutting force. A chopper pump generates roughly one-tenth the force.

    http://www.pwmag.com/Images/tmp6697%2Etmp_tcm111-1693142.jpg

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    Unlike a high-speed, low-torque chopper pump, a sewage grinder is a low-speed, high-torque piece of equipment. A 29:1 gear reducer enables this 10-hp JWC Environmental grinder to deliver 45,000 pounds of cutting force. A chopper pump generates roughly one-tenth the force.

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    Dean Wiebenga

    Unlike a high-speed, low-torque chopper pump, a sewage grinder is a low-speed, high-torque piece of equipment. A 29:1 gear reducer enables this 10-hp JWC Environmental grinder to deliver 45,000 pounds of cutting force. A chopper pump generates roughly one-tenth the force.

  • After substantial outreach, residents still think its OK to flush consumer goods  as Portland Water District employee Tom Hume points out  because packaging isnt prominently labeled dont flush.  To identify and quantify whats clogging pumps, use the Maine Wastewater Control Associations Pump Clog Standard Operating Procedure at http://go.hw.net/PWpumpclogs.

    http://www.pwmag.com/Images/tmp73B8%2Etmp_tcm111-1693144.jpg

    true

    After substantial outreach, residents still think its OK to flush consumer goods as Portland Water District employee Tom Hume points out because packaging isnt prominently labeled dont flush. To identify and quantify whats clogging pumps, use the Maine Wastewater Control Associations Pump Clog Standard Operating Procedure at http://go.hw.net/PWpumpclogs.

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    Michelle Clements/Portland Water District

    After substantial outreach, residents still think it’s OK to flush consumer goods — as Portland Water District employee Tom Hume points out — because packaging isn’t prominently labeled “don’t flush.” To identify and quantify what’s clogging pumps, use the Maine Wastewater Control Association’s Pump Clog Standard Operating Procedure at http://go.hw.net/PWpumpclogs.

  • A chopper pump slices debris as it pumps sewage. This takes more electricity but requires less maintenance vis-à-vis clogs.

    http://www.pwmag.com/Images/tmp78AB%2Etmp_tcm111-1693145.jpg

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    A chopper pump slices debris as it pumps sewage. This takes more electricity but requires less maintenance vis-à-vis clogs.

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    Vaughan Co. Inc.

    A chopper pump slices debris as it pumps sewage. This takes more electricity but requires less maintenance vis-à-vis clogs.

Click here for Part 1


1) Screen it

Portland Water District
Portland, Maine

PROBLEM

The Portland Water District provides wastewater services to six communities in southern Maine. Assets include 72 pump stations ranging from an ejector station serving several homes to the state’s largest at 50 mgd; four treatment plants; and 96 miles of pipe.

The capital improvement plan included upgrading a pump station that feeds a 4.54-mgd treatment plant. Shortly after installation, the new pumps began to plug at the onset of wet weather. Two of the four pumps would fail completely. The other two would keep running with the clogs intact, making the entire facility vibrate.

Made entirely of baby wipes, according to Portland Wastewater Services Director Scott Firmin, the clogs were physically degrading the pumps. The district considered three possible solutions:

  • New cutter pumps or impeller modifications. Rejected; available electrical power at the station limited possible pump modifications.
  • A channel grinder. Rejected; equipment couldn’t easily accommodate station configuration and flow ranges, and instead of removing material would pass it along to the plant where there could be downstream issues.
  • Screens. Accepted; the station already had a coarse bar rack, so it could accommodate a screen.

SOLUTION

Equipment: Mahr continuous-rake screen with ½-inch bar spacing. It’s a front-raked, front-return bar screen with multiple rake bars mounted to chains located on each side of a self-contained frame to prevent solids carryover.

Manufacturer: Headworks Inc.
www.headworksusa.com

Equipment: Model EWP 250-600A washing press to control odor by rinsing organic matter out of screenings material.

Manufacturer: Vulcan Industries Inc.
www.vulcanindustries.com

AEC firm: CDM, using design-build EPCM (engineer-procured contract management) with a $4 million guaranteed maximum price

Project cost: $3.74 million

FOR MORE INFORMATION
Scott Firmin
sfirmin@pwd.org
207-774-5961, ext. 3077
Portland Water District
www.pwd.org

Next page: 2) Replace the pump