The document proposes modifications to an ordinance regarding new sump pump discharges. The revised ordinance would provide four key benefits: 1) Help prevent sewage backups during rain events by reducing pressure on small diameter combined sewers from multiple sump pumps; 2) Make the code consistent with current city policy; 3) Minimize environmental impacts by reducing greenhouse gas emissions from pumping and treating clear sump pump water; 4) Define requirements to obtain permission to connect sump pumps to the sewer system. The proposed revisions include a clearly laid out waiver policy developed by three city departments.

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Ordinance 76-O-12: Subsoil Drain Pipe
Proposed Modifications Regarding
New Sump Pump Discharges
September 24, 2012

2. Proposed modification would only
affect new sump pump discharges
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3. Location of Existing Storm Sewers
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4. Revised ordinance would provide
four key benefits to the City
1. Help prevent sewage backups during rain
events.
2. Make code consistent with current policy
and other sections of the code.
3. Minimize the environmental impacts of sump
pump discharges.
4. Defines requirements to obtain permission to
connect to the sewer system
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5. Preventing sewage backups during
rain events
Relief sewer improvements and restrictors
successfully reduced basement backups
resulting from surface runoff.
Sump pumps directly connected to the combined
sewers still have the potential to cause
basement backups.
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6. Preventing sewage backups during
rain events
63% of combined sewers are ≤ 12” diameter.
At an average slope of 0.4%, the capacity of a 12”
sewer is about 744 gpm.
Typical sump pump capacity is 40 gpm  18 sump
pumps could overwhelm an entire 12” sewer.
Therefore, 12” and smaller combined sewers act
mostly as sanitary sewers, with limited capacity
for sump pump discharges.
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10. Consistency with City policy and
other portions of the City Code
“Footing drains shall be connected to the sump
pump and discharge shall be made to the storm
or combination sewers, and not to sanitary
sewers.”
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11. Environmentally friendly policy
Assuming 30 minutes of sump pump operation
and 40 gpm capacity, every 1,000 sump pumps
would discharge 1.2 million gallons of clear water
to the combined sewer during a rain storm.
1.6 million tons of CO2 is produced for every 1,000
sump pumps operating during a rain storm (for pumping
and treatment at MWRD facilities)
More environmentally responsible to discharge to the
ground surface and allow at least a portion of the flow to
infiltrate into the soil before it reaches street inlets.
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12. Proposed revisions include a clearly
laid out waiver policy
Community & Economic Development, Public
Works, and Utilities Departments collaborated to
clarify waiver policy.
Ordinance provides clearly defined requirements
to obtain permission to connect to the sewer
system.
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QUESTIONS
Ordinance 76-O-12: Subsoil Drain Pipe
Proposed Modifications Regarding
New Sump Pump Discharges
September 24, 2012