NPDES Storm Water MSGP: Visual
Examinations |
All facilities covered by
the MSGP (except for Sector S - Air Transportation Facilities) are
required to perform quarterly visual examinations of their storm water
discharges for the purpose of visually inspecting storm water quality
associated with storm water runoff or snow melt. Visual examinations
provide a simple and inexpensive means of obtaining a rough assessment of
the effectiveness of a facility's SWPPP.
Visual examinations should be:
- Performed at least once per quarter for the life of the permit
(quarters are defined as: Jan-Mar, Apr-Jun, Jul-Sep and Oct-Dec)
- Completed in a well lit area
- Based on samples collected within the first 30 minutes of discharge
(or as soon as practical, not to exceed 60 minutes)
- Performed by the same person each quarter for the duration of the
permit (where practical)
- Examined for odor, color, clarity, floating solids, settled solids,
suspended solids, foam, oil sheen and other obvious indicators of storm
water pollution
- Recorded in the Storm Water Pollution Prevention Plan
Exception:
Coal mining-related facilities (Sector H) must perform visual
monitoring within the first 60 minutes of discharge (or as soon thereafter
as practical, but not to exceed 2 hours). Visual examinations are not
required for inactive areas not under Surface Mining Control and
Reclamation Act (SMCRA) bond. However, visual examinations must be
performed:
- Quarterly for active areas under SMCRA bond located in areas with
annual precipitation greater than 20 inches; and
- Semi-annually for inactive areas under SMCRA bond, and active areas
under SMCRA bond located in areas with average annual precipitation of
20 inches or less. At least one examination must be performed during
each of the following periods: January through June and July through
December.
What Documentation Should be Prepared?
Visual examination reports must include:
- Examination date and time
- Examination personnel
- Nature of discharge (i.e., runoff or snowmelt)
- Visual quality of the storm water discharge
- Probable sources
Do Visual Examination Results Need to be Reported?
No, unless specifically requested to do so by EPA. All results must be
recorded and kept with the Storm Water Pollution Prevention Plan.
Do All Discharge Points Need to be Visually Examined?
No. Under certain conditions, a facility may determine one outfall to
be a Representative Discharge. That is, the facility reasonably believes
the discharge from two or more outfalls is substantially identical and
therefore only inspects one outfall. Facilities must document their
rationale for considering two outfalls to be identical and contain that
explanation in the Storm Water Pollution Permit. Also, for each
representative outfall, an estimate the size of the drainage and an
estimate of the runoff coefficient of the drainage area must also be
provided in the SWPPP. More information on Representative Discharges
can be found in the Introductory Fact Sheet to the MSGP (Section
VI.E.6).
What If a Visual Examination Can't be Performed?
The MSGP allows for waivers from visual examination requirements under
two circumstances: adverse weather conditions, and unstaffed and inactive
sites. It should be noted that these waivers cannot be used for compliance
monitoring requirements associated with effluent limitations.
Adverse Weather Waiver
Adverse weather conditions that may prohibit the collection of samples
include weather conditions that create dangerous conditions for personnel
(such as local flooding, high winds, hurricanes, tornadoes, electrical
storms, etc.) or otherwise make the collection of a sample impracticable
(drought, extended frozen conditions, etc.).
The facility must document reasons for not
performing the visual examination if adverse climate conditions preclude
the discharger from performing the visual examination. The facility
must retain these records with the SWPPP.
Unstaffed and Inactive Sites
The facility must maintain a certification with the storm water
pollution prevention plan stating that the site is inactive and unstaffed
and that performing visual examinations during a qualifying event is not
feasible.
. |