Salisbury Public Works   

   A Team of Teams Making A Difference !   

The City of Salisbury experienced a Combined Sewer Overflow event at the South Side Pump Station on Saturday, October 8, 2005 from 5:45 PM to 8:45 PM following an intense and lengthy rainstorm on most of Saturday.  The on-duty maintenance staff responded to an alarm at the South Side Pump Station.   It is estimated that 440,420 gallons of wastewater and stormwater was discharged into the Wicomico River in the vicinity of Ridge Road.  The Wicomico Board of Health, Maryland Department of the Environment, and the Federal Government's Environmental Protection Agency have been notified.  The City is posting notification by signage and a press release to the media.  The City of Salisbury is testing the water quality of the river on a regular basis and providing the results to the Wicomico County Board of Health for their analysis. 

Introduction.    The Public Works Department has been steadily working since the mid-80s at reducing Combined Sewer Overflows and Sanitary Sewer Overflows.   It is a long-term challenge for the City due to the complexity and large capital outlay required to solve it.  To date, the City has separated over 75% of its combined sewer systems and spent over $1.325 million.  The Department has an additional $562 thousand programmed for future projects.

Definitions.  A Combined Sewer Overflow (CSO) occurs when a combination of stormwater and wastewater flows out of the waste water collection system such as a sewer, lift station, pump station, or the waste water treatment plant as a result of the system exceeding its hydraulic capacity.  CSOs can be caused by heavy rains or a rapid snow melting which cause water runoff to enter the wastewater collection system through local flooding and/or stormwater facilities feeding into the sanitary sewer system.  These high surges of stormwater overwhelm the stormwater collection system and overflow into the sanitary system and cause the system to back-up and overflow. 

Clean Water Act.   The EPA's National CSO Policy, now codified at Section 402 of the Clean Water Act, requires the City of Salisbury to meet one of three criteria specified in EPA's "presumption" approach which are:

• No more than an average of four overflow events per year; or

• The elimination or capture for treatment of no less than 85% by volume of the combined sewage collected in the CSS during precipitation events on system-wide annual average basis; or

• The elimination or removal of no less than the mass of pollutants, identified as causing water quality impairment through the sewer system characterization, monitoring, and modeling effort, for the volumes that would be eliminated or captured for treatment under paragraph ii.

You can view an extract from the EPA's web page at National CSO Policy.

Our performance record in accordance with the EPA’s National CSO Control Policy  guidelines under the “presumption” approach shows that in the last four years we easily met not just one, but two of the criteria.  Specifically:

• We averaged 2 CSO events per year for the last 4 consecutive years as compared to EPA's requirement of an average of 4 CSO events per year.

• We have a CSO capture rate ranging from 99.6% to 99.9% for the last 4 consecutive years during precipitation events as compared to EPA's requirement of 85%.

Our performance data is contained in the following table:

        

Year	# of CSO Events	Meet EPA Goal of 4?	Total CSO Volume	Total WWTP Flow	Total Flow Capture %	WWTP Precip Flow	Precip Flow Capture %	Greater than 85% EPA Goal?
1997	1	Yes
1998	2	Yes	1,854,975	1,924,381,250	99.904%	551,041,650	99.663%	Yes
1999	2	Yes	75,100	1,950,115,860	99.996%	608,153,700	99.988%	Yes
2000	2	Yes	232,070	1,958,300,900	99.988%	338,227,500	99.931%	Yes
2001	2	Yes	595,646	1,431,153,100	99.958%	491,309,630	99.879%	Yes
Total
Average

Maryland's CSO Communities.  There are eight designated CSO communities in Maryland.  They are Allegany County, City of Baltimore, Cambridge, Cumberland, La Vale, Frostburg, Salisbury, and Western Port.  According to the Maryland Department of the Environment's Report on CSOs in Maryland for the period from ____ to ___, the CSO communities (rank ordered by number of CSO events) have experienced are:

      

Community	# of CSOs	CSO Volume  (gallons)
Frostburg	269	7,200,092
La Vale	116	30,946,118
Cumberland	64	64,499,421
Cambridge	30	16,555,900
Salisbury	3	1,053,646
City of Baltimore
Total
Average

City's Combined Sewer Overflow (CSO) Reduction Action Program

Purpose.  To provide a project and work effort summary and future action plan by the City of Salisbury to reduce CSOs.

                         Project Name                        Date                        Cost

·     

Fiscal Year 2000

                         Project Name                        Date                        Cost

·        Manhole Retrofit and Dust Covers                  Fall 99                  $   15 K

Installed hundreds of sanitary sewer manhole seals to prevent rainwater and flood water from entering the sanitary sewer system.  Completed 78 out of 80 (98%) manhole repairs and upgrades consisting of dust covers installation, repaired frames to corbels and chimney seals in the Mill Street Area.  The remaining two manholes need extensive rehabilitation.  They are scheduled for repair in FY 2002.

·        Isabella Street Area.                  Sep-Nov 99                  Negligible

Separated downspouts at a private residence on East Isabella Street. Replaced all Isabella Street clean out plugs.

·        South Side Pump Station Emergency Generator.                  Nov 99                  $   35 K

·        West Main Street Pipe Diversion.                  Spring 00                  $   10 K

Fiscal Year 2001

                         Project Name                        Date                        Cost

·        Fitzwater Street Manhole Repair                   Aug 00                  $   13 K

Rebuilt Fitzwater Street manhole and sanitary sewer line, which eliminated major ground water inflow and thereby reducing loading to the sewage collection system.

·        Baysinger Trailer Park.                   Oct 00                  Negligible

Eliminated stormwater runoff inflow to the sewage collection system at a trailer park 

                         Project Name                        Date                        Cost

·        Truitt Street Area.                  Jun 01                  Negligible

Replaced all Truitt Street clean out plugs.

·        City Zoological Park.                  Oct 99                  Negligible

Implemented a manual shut off of the Salisbury Municipal Zoo Lift Station at high tide.  The shutoff avoids overloading sanitary sewer lines tributary to Church and Mill Street Lift Station and resultant backflow into basements.

·        Camden Avenue Neighborhood                  Nov/Feb 01                  Negligible

Separated downspouts at six private residences on Middle Boulevard and Camden Avenue.

·        Fitzwater Street Pump Station.                  Apr 01                  $   35 K

Installed an emergency generator at the Fitzwater lift station to ensure emergency power for the lift station due to the high effluent flows from the Perdue Processing plant.

Fiscal Year 2002

                         Project Name                        Date                        Cost

·        Air Business Park.                  Aug 01                  $  6 K

Regrouted two leaking manholes at the Air Business Park. Additionally, repaired three clean outs.

·        Truitt Street CSO Separation/Flood Relief                  Jul 01                  $ 450 K

Awarded a $ 450,000 construction contract in July 2001 to separate a stormwater line from a sewer main.  Construction initiated in September 2001.  Project removes 11-acres of storm water runoff from the sanitary sewer collection system. Scheduled completion is January 2002.

·        WWTP/Collection System SCADA                      $ 100 K

Funded the installation of the Supervisory Control and Data Acquisition (SCADA) system for $100 K for the wastewater collection and treatment systems and $119 K for the water treatment and distribution system for a total of $219 K.

·        Manhole Rebuild (Part II)                       $   5 K

o       Rebuild a Fitzwater Street Manhole              

o    Rebuild Manholes # 3 and # 4 located in the Mill Street Area.  These are the manholes that were not completed in FY 00.

Fiscal Year 2003 

                         Project Name                                     Cost

·        Down Buildings & Other Possible CSO Areas.

o       Phase 2 Engineering Services.                   $   96 K

o       Wall penetration with downspouts.             $ 104 K

o       Plaza storm drain separation.              $   27 K

Fiscal Year 2004

                         Project Name                                     Cost

·        Down Buildings & Other Possible CSO Areas.

o       Phase 2 Engineering Services.                   $   40 K

o       Trim downspouts and plug.                $   10 K

o       Wall penetration with downspouts.             $   80 K

Fiscal Year 2005

                         Project Name                                     Cost

·        Down Buildings & Other Possible CSO Areas.

o       Building drain separation.              $   40 K

o       Storm drain separation.              $   60 K

Completed Actions to Reduce CSOs.

• Developed nine minimum control plans to reduce CSO discharges in August 1997.

• Developed an Operations and Maintenance Manual for the Sanitary and Combined Sewer Systems in August 1997.

• Separated the 12” stormwater pipe from the sanitary sewer pipe going to Church and Mill Street Lift Station in the Fall of 1997.

• Conducted an extensive review of the sanitary sewer system to develop a long-term CSO control plan in March 1999. 

• Installed hundreds of sanitary sewer manhole seals to prevent rainwater and flood water from entering the sanitary sewer system.

• Implemented a manual shut off of the Salisbury Municipal Zoo Lift Station at high tide.  The shutoff avoids overloading sanitary sewer lines tributary to Church and Mill Street Lift Station and resultant backflow into basements.

• Rerouted a manufacturer's truck wash area away from the sanitary sewer to their pretreatment facility.  This decreased the organic wastewater loading into the sanitary sewer system.

• Repaired cleanout of a private residence on Viewfield. 

• Rebuilt Fitzwater Street manhole and sanitary sewer line, which eliminated major ground water inflow and thereby reducing loading to the sewage collection system.

• Eliminated stormwater runoff inflow to the sewage collection system at a trailer park.

• Completed 78 out of 80 (98%) manhole repairs and upgrades consisting of dust covers installation, repaired frames to corbels and chimney seals in the Mill Street Area..  The remaining two manholes need extensive rehabilitation.

• Replaced all Truitt Street clean out plugs.

• Regrouted two leaking manholes at the Air Business Park. Additionally, repaired three clean outs.

• Separated roof drains at 7 of 26 addresses.

• Repaired a two-way clean out on Holland Avenue.

• Separated downspouts at a private residence on East Isabella Street. 

• Replaced all Isabella Street clean out plugs.

Current Actions to Reduces CSOs.

• Funded the installation of the Supervisory Control and Data Acquisition (SCADA) system for $ 100,000 for the waste water collection and treatment systems and $ 119,000 for the water treatment and distribution system for a total of $ 219,000 in June 2001. 

• Awarded a $ 450,000 construction contract in July 2001 to separate a stormwater line from a sewer main.  Construction initiated in September 2001.  Project removes 11-acres of storm water runoff from the sanitary sewer collection system. Scheduled completion is January 2002.

• Rebuild Manholes # 3 and # 4 located in the Mill Street Area.

• Need to separate roof drains at nineteen addresses.

• Need to separate Plaza  stormwater drains from the sanitary sewer system at four locations.

1998

1999

  2000

  2001

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If you have any questions, corrections, or comments on the Public Works web pages, please contact John F. Jacobs at the City of Salisbury Department of Public Works at (410) 548-3170.