MEC&F Expert Engineers : TIPS FOR MINIMIZING STORMWATER POLLUTION

Thursday, February 5, 2015

TIPS FOR MINIMIZING STORMWATER POLLUTION



TIPS FOR MINIMIZING STORMWATER POLLUTION

Permits for stormwater discharges associated with industrial facilities, issued by both the U.S. Environmental Protection Agency (EPA) and states with permitting authority, pose a variety of requirements on regulated facilities, but smart facility operators can be proactive to minimize runoff and stay in compliance. Today and tomorrow, we will look at recommendations from the EPA to control stormwater impacts and potentially reduce the regulatory burden.

Simple Steps for Minimizing Stormwater Pollution
Stormwater runoff is the major contributor to the ongoing degradation of our nation’s surface and groundwater. Although we cannot control precipitation, there are plenty of ways to control its impact through measures that are both common sense and required by law. Here are some of EPA’s recommended measures for commercial/industrial facilities to do their part in minimizing stormwater pollution.

1. Detect and eliminate illicit connections, which the EPA defines as “illegal and/or improper connections to storm drainage systems and receiving water …” The discharge of industrial waste via illicit connections is illegal because most such discharges would normally require a National Pollutant Elimination System (NPDES) permit with specific discharge requirements. Unfortunately, illicit storm system connections can exist without the knowledge of facility operators, increasing the potential for illegal discharges. 

Facility operators should also note that local ordinances may authorize municipalities to inspect facilities for illicit connections, especially when they are suspected of releasing contaminated discharges into storm drain systems. For example, when pollutants are found in stormwater systems and no source is readily identified, local and/or state environmental agencies may be prompted to investigate all possible sources. As with all regulatory requirements, ignorance is no defense and even facility owners and operators that were unaware of an illicit connection could be found liable.

2. Even when not already required by other regulations, training and educating employees (and customers if applicable) can help to build good pollution prevention practices and get everyone on board. The EPA recommends a number of things to consider in such training:

Information on material handling and spill prevention and response to better prepare employees in case of an emergency;
Training on the purpose, operation, and maintenance of pollution prevention management practices; and
Ongoing education with periodic training courses and with signs that remind workers of their responsibility to use good housekeeping practices.
With regard to customer education, the EPA recommends informing them of the company’s efforts to reduce waste and pollution and the use of signage or written materials “so they will be less likely to contribute to pollution problems that are ultimately the responsibility of the business.”

3. General good housekeeping practices can also go a long way toward minimizing polluted stormwater runoff, and they are also among the least expensive and most effective. While specific practices are often facility and process specific, there are several common ones that apply to most. These include:

Limit the exposure of materials that can be eroded or dissolved by rainfall and runoff by creating an inventory of all materials on-site that are exposed to rain and runoff and implementing appropriate exposure-reduction activities and policies.

Keep dumpsters and other containers securely closed, store containers under cover, and cover stockpiled materials, such as gravel, wood chips, and building materials with plastic sheeting. 

Maintain outdoor areas and keep them clean of litter, garbage, and other refuse. The EPA recommends such cleanup activities be undertaken without using water or other means that could wash refuse, grit, grime, and sediments into the storm drain system. Instead, pick up, sweep, and dispose of nonhazardous refuse in the garbage and use absorbent materials such as manufactured absorbent snakes, kitty litter, or sawdust to absorb liquid contaminants.

4. Another good way to focus operations on source reduction is to conduct an environmental audit. 

According to the EPA, “a reduction assessment can be performed to evaluate the type and amount of materials currently used, processes conducted, and wastes generated.” The results of the assessment can reveal “recommendations for modifying the commercial process to generate less waste, using alternative raw materials to generate non-hazardous wastes, and identifying recycling options to reduce the amount of wastes that require disposal.” 

Minimizing the potential for pollution from contaminated stormwater runoff from industrial facilities is good for the environment and the bottom line. Beginning yesterday and continuing today we are reviewing some of Environmental Protection Agency’s (EPA) recommendations that can help control stormwater impacts at industrial facilities.

5) Although many facilities are required by different regulations to implement spill prevention, control, and cleanup plans, even those that are not should consider the potential benefits. The EPA recommends the following aspects to incorporate in such plans:

Spill prevention is the best way to avoid contaminated runoff so plans should cover the careful storage of materials in sound, clearly labeled containers, and the regular inspection and maintenance of equipment;

Outdoor storage of materials should include provisions for keeping containers covered and kept on a paved area to protect them from being mobilized by wind and runoff. Storage areas that are not under a roof “should be designed to drain with a slight slope (approximately 1.5 percent) to an area that will provide treatment prior to disposal. Runoff from other areas should be excluded to reduce the volume of runoff requiring treatment by installing berms, curbs, or diversions on the perimeter of the storage area;”

For outdoor liquid storage, secondary containment should be implemented and runoff or spills from the containment area should be directed to the sanitary sewer (where permissible) or to an appropriate storage or treatment facility for reuse or disposal;

Spill handling procedures should be well-defined for any materials that might be exposed to rainfall or runoff and should cover both small and large spills, including requirements for contacting emergency personnel; 

Spill procedures should also “emphasize that spills must be cleaned up promptly and should specify how each type of material should be handled,” and that use of water for cleanup is strongly discouraged; and
Drains or inlets to storm sewers should be plugged during spill remediation to prevent off-site export of pollutants

6) Keeping equipment clean and well maintained often requires outdoor washing and other operations that can result in contaminated runoff. To practice safe equipment washing and maintenance, the EPA recommends adhering to the following pollution prevention measures: 

Water that results from the cleaning of industrial equipment “must be discharged as process wastewater to the sanitary sewer and is not allowed in storm drains, in most cases;”

For cleaning greasy equipment or trucks, the EPA recommends designating a special cleaning area with  “equipment installed to capture, pre-treat, and discharge the wash water to the sanitary sewer;”

To help ensure washing and other activities with spill potential are only conducted in the appropriate areas, the EPA recommends posting instructional signs that prohibit changing vehicle oil, washing with solvents, and other activities in nonwash areas; 

Systems such as sumps and drain lines should be installed to collect washwater for treatment and discharge to the sanitary sewer; and

During vehicle maintenance activities, the EPA first advises that such operations be performed indoors and that all waste materials be properly stored and disposed of or recycled. When performing maintenance work outdoors, “all oil and grease should be captured unless precautions are taken to prevent them from being carried in runoff, such as with the use of absorbent pads in inlets or grates.”

7) When performing construction, repairs, or remodeling activities, the EPA says there are several precautionary steps that can be taken to minimize the potential for stormwater contamination, including:

Mixing paints only in areas where paint spills can be easily recovered or cleaned, and using impermeable ground cloths;

Proper management of paint chips and scrapings to prevent contamination of water or soil (including any additional requirements for lead-based paint);
Storing paint buckets and barrels of materials where they will not be in contact with runoff;

Performing cleanup of water-based paint brushes and equipment in a sink connected to the sanitary sewer, while oil-based paint brushes and equipment must be stored or recycled;

Hanging drop clothes or draperies during spray painting to shield the user from the wind, collect overspray, and minimize the spreading of windblown materials; and
Placing a tarp or ground cloth beneath sand blasting activities to capture the blasting medium, protect the work area from wind, and capture airborne particles.