Aurora Public Schools
Standard Operating Procedures
for Stormwater Management
Graffiti Removal
Summary
This work practice covers the procedure for Graffiti Removal set-up and discharge of waste
water.
Examples
The following are examples of work that can be performed using this procedure. If job
conditions vary from the examples, stop work and notify the Environmental Compliance Branch.
A.
B.
C.
D.
Pre-planning
Site Visit
Drain Location for discharge
Graffiti Removal
Related Work Practices
A.
B.
C.
D.
E.
Catch basin set up for little to no spillage of waste water
Collection and Release to Sanitary Sewer (Requires Prior Metro Wastewater Approval)
Drainage to Vegetation – Plain water or Wet Baking Soda
Evaporation in Place – see Work Practice
PPE – Safety Glasses and Nitrile Gloves
Regulatory Information
A State Stormwater Permit is not required for this procedure, however, the State of Colorado
Discharge of Process Wastewater from Power Washing Operations regulation (attached) must be
followed. The Environmental Compliance Branch must be notified of spills or if additional
assistance or guidance is needed.
Worker Recommendation
At least one worker will be required for this procedure. The worker is to set up a catch basin for
containing the water, debris, and/or chemical mix. The worker will clean the surface while
monitoring the flow into the basin. The worker is also in charge of neutralization and pH
monitoring prior to pumping the water to the sanitary drain.
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2/9/2016 3:12 AM
Aurora Public Schools
Standard Operating Procedures
for Stormwater Management
Graffiti Removal
Work Practice
A.
B.
C.
D.
E.
F.
G.
Aurora Public Schools’ approved chemicals for graffiti removal are:
Set-up will be site specific but needs to include a procedure to capture all water, debris,
and chemical to be pH tested and diluted, if necessary, before being discharged to the
sanitary sewer. The site needs to be inspected prior to beginning any work to determine
the location of storm drains in the area. These areas need to be protected in the event of
accidental discharges.
Procedure
a. Wear appropriate personal protection equipment. Read MSDS for specific
requirements. Avoid contact with skin and clothing.
b. Different options for removing graffiti may include plain water, baking soda (wet
or dry), chemical, and walnut shells.
Neutralization – pH must be adjusted to between 5 and 9 before entering the sanitary
sewer. The Environmental Compliance Branch has a pH meter that can be used to
monitor the pH. pH can be adjusted using vinegar or baking soda depending on the pH of
chemical used. pH must be monitored continuously throughout the procedure.
Disposal
a. Vegetation: Plain water or water and baking soda can be discharged onto
vegetative cover providing no ponding or run-off occurs. All solid debris (i.e.
paint chips, gum, etc) must be collected and disposed of in site dumpster.
b. Sanitary Sewer: Water and chemical must be pH tested and adjusted as needed to
be between 5 and 9. Once pH is in the appropriate range and free of solid waste
debris, the waste water can be disposed of in the sanitary sewer.
c. Solid Waste Disposal: When dry soda or walnut shells are used, these must be
vacuumed or swept up and disposed of in the site dumpster.
d. If the above methods are not an option, please contact the Environmental
Compliance Branch for alternative disposal methods.
Documentation – The technician must complete the “Aurora Public Schools Graffiti
Removal Record Keeping” form for EVERY event. The information on this form must
include the site being cleaned, the method or chemical used, where the discharge
occurred, and the amount of both water and chemical used. Copies of this form are
available from the Environmental Compliance Branch.
Prohibited activities
a. Use caution if performing procedure in windy conditions.
b. No discharge is allowed to enter the storm drain system.
c. All solid waste debris must be swept or vacuumed and disposed of properly.
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Aurora Public Schools
Standard Operating Procedures
for Stormwater Management
Graffiti Removal
Discharge Regulatory Flow Chart
Process or chemical
used
Water
only
Discharge
to
Vegetation
Wet
Baking
Soda
Discharge
to
Vegetation
Dry Soda
Contain,
adjust pH,
and
discharge
to sanitary
Sweep or
vacuum
Chemical
Walnut
Shells
Contain,
adjust pH,
and
discharge
to sanitary
Sweep
and
vacuum
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