Image of a person document findings while inspecting an outfall
It is generally easier and less expensive to prevent pollution at the source than restore a surface waters once they're polluted. Permitted municipal separate storm sewer system (MS4) communities are the first line of defense for many pollutants entering storm sewer systems within their jurisdiction, such as
- sand and salt for de-icing
- fertilizers and pesticides on municipal properties
- vehicle fueling and maintenance chemicals
Minimum Control Measure (MCM) 6 in the MS4 General Permit requires permittees to maintain a operations and maintenance program to prevent or reduce pollutant discharges from municipally owned or operated properties. The program must include:
- A Facility Inventory that documents municipally owned/operated facilities that may pollute stormwater. See the Facility Inventory Template for more information and a template to use.
- Best management practices (BMPs) to prevent or reduce the stormwater impacts from the facilities documented on the Facility Inventory.
- BMPs to protect Source Water Protection Areas, such as Drinking Water Supply Management Areas and source water protection areas for surface intakes.
- Pond assessment procedures and schedule to evaluate the effectiveness of total suspended solids (TSS) and total phosphorus (TP) removal of municipally owned/operated ponds.
- Inspections of structural stormwater BMPs annually, at least one inspection of ponds and outfalls during the permit term, and quarterly inspections of stockpiles and storage and material handling areas documented in the Facility Inventory.
- Maintenance of structural BMPs, outfalls, and ponds based on the results of the inspections detailed above.
- Employee training as appropriate for the employee's position. Training should address the importance of protecting water quality and describe relevant MS4 General Permit requirements. The training should have a schedule that established initial training for new and seasonal employees and recurring training for existing employees.
- Documentation detailed here.
Additional resources: