Proper hazardous material storage
A hazardous material is any biological, chemical, or physical material with properties that make it dangerous or potentially harmful to human health or the environment. Hazardous materials can be released to the environment in a variety of ways.
When hazardous material comes into contact with rain or snow, the pollutants are washed into the storm sewer system and, ultimately, to surface water bodies and/or ground water. Hazardous materials have negative impacts on fish habitat, ground water drinking water sources, and recreational uses of Minnesota’s lakes and streams. A spill of only one gallon of oil can contaminate one million gallons of water. Hazardous materials associated with MS4s and their operations include, but are not limited to, oil, gasoline, antifreeze, fertilizers, pesticides, and de-icing agents and additives.
This fact sheet provides guidance on storage and handling of hazardous materials.
Benefits and pollution reduction
Minimizing or eliminating contact of hazardous materials with stormwater can significantly reduce pollution of downstream waters. Proper hazardous material handling and storage also contributes to employee health, an organized work place, and efficient operation.
Program development and implementation
Hotspot facilities are facilities that produce higher levels of stormwater pollutants and/or present a higher potential risk for spills, leaks or illicit discharges. Hazardous material storage and handling is of particular concern in these areas. Common Municipal Separate Storm Sewer System (MS4) owned or managed hotspot facilities are those that handle solid waste, wastewater, road and vehicle maintenance, and yard waste, such as
- composting facilities,
- equipment storage and maintenance yards,
- hazardous waste disposal facilities,
- hazardous waste handling and transfer facilities,
- landfills, and
- materials storage yards
Hazardous material handling, loading, and unloading pollution prevention practices
- Avoid loading/unloading materials in the rain and/or provide cover for the activity
- Retrace areas where materials have been transferred to identify spills and immediately clean them up
- Time delivery and handling of materials during favorable weather conditions whenever possible (e.g. avoid receiving loads of sand during windy weather)
- Inspect containers for material compatibility and structural integrity prior to loading/unloading any raw or waste materials
- Use dry cleanup methods (e.g. squeegee and dust pan, sweeping, and absorbents as a last step) in case of spillage rather than hosing down surfaces
- If your MS4 operates loading docks, provide cover and provide grading or berming to prevent run-on of stormwater
Material storage pollution prevention practices
- Confine material storage indoors to the greatest extent feasible, and plug or disconnect floor drains that lead to the stormwater system
- Confine outdoor material storage to designated areas that are covered, away from high traffic areas, outside of drainage pathways, and on impervious surfaces
- Store containers on pallets or equivalent structures to facilitate leak inspection and to prevent contact with wet floors that can cause corrosion. This technique also reduces incidences of container damage by insects, rodents, and etc.
- Store materials and waste in materially compatible containment units
- Keep hazardous materials in their original container
- If not in their original container (e.g. used motor oil), clearly label all storage containers with the name of the chemical, expiration date and handling instructions
- Maintain an inventory of all raw and waste materials to identify leakage and order new materials only when needed
- Provide secondary containment for storage tanks and drums with sufficient volume to store 110 percent of the volume of the material
- Provide sufficient aisle space to allow for routine inspections and access for spill cleanup
- Inspect storage areas for spills or leaks and containment units for corrosion or other failures
Vehicle and equipment maintenance pollution prevention practices
- Implement good housekeeping including emptying and cleaning drip pans and containers rather than leaving them full and open around the shop
- Dispose of greasy rags, oil filters, air filters, batteries, spent coolant, and degreasers following MPCA or county hazardous waste guidelines
- Use drip pans, drain boards, and drying racks to direct drips back to a fluid holding tank for reuse or proper disposal
- Avoid hosing down areas that would result in polluted runoff discharging to a stormwater system
- Do not pour liquid waste into sinks, floor drains, outdoor storm drain inlets or other storm drains or sewer connections
- Clean equipment and vehicles regularly to remove accumulated dust and residue
- Perform all cleaning operations indoors or under cover when possible
- If washing vehicles outdoors see the Vehicle Washing fact sheet for more information.
Vehicle and equipment fueling pollution prevention practices
- Fuel vehicles only in designated areas that are covered
- Avoid topping off fuel tanks to prevent spills from overfilling
- Prevent run-on of stormwater into fueling areas using diversion dikes, berms, curbing, surface grading or other measures or use catch basin inserts to prevent discharge into storm drains
- Provide barriers around fuel pumps to prevent collisions with vehicles
- Use fueling hoses with check valves to prevent hose drainage after filling
Waste treatment, disposal, and cleanup pollution prevention practices
- Adopt a regular schedule for the pick up and disposal of waste materials
- Recycle leftover materials whenever possible
- Substitute nonhazardous or less hazardous materials for hazardous materials wherever possible
Specific materials control
Other fact sheets developed for this guidance document provide hazardous material storage and handling procedures for specific materials.
Spill prevention, control and countermeasure (SPCC) plan
Spill prevention plans are created for prevention as opposed to after-the-fact reactive measures. Specifically, SPCC Plans are required by the EPA for oil spill prevention at facilities that meet the following three criteria:
- having an aggregate aboveground storage capacity greater than 1,320 gallons or a complete buried storage capacity greater than 42,000 gallons, and
- have a reasonable expectation of a discharge into or upon navigable waters of the United States.
Remember that a spill of only one gallon of oil can contaminate a million gallons of water. Even if an SPCC is not required at your facility, spill prevention plans for any and all hazardous materials can be an effective preventive measure and training tool (see Employee Training below), and SPCC Plans provide a good framework for any type of spill prevention plan. For details on what to include in spill prevention plans see the EPA (see  and ) and MPCA guidance documents.
Municipalities and other regulated MS4s can greatly reduce potential water quality impacts by creating chemical application programs and training all full time and seasonal employees that are responsible for handling hazardous wastes. Consider registering city staff into existing training programs or providing in-house training. In-house training could include the development of guidance documents for trainees to keep with them on the job site.
Maintenance of loading/unloading areas, storage areas and containers, and equipment, as described above, is inherent for proper storage and handling of hazardous materials.
Pollution prevention measures are not inherently costly and are more a matter of culture. However, providing cover over hazardous materials stored outdoors can be equivalent to the cost of a pole building (💲5 to 💲12 per square foot) and a concrete slab (💲3 to 💲6 per square foot). If waste reduction measures are taken, an accurate inventory is maintained, and regular waste disposal is implemented, MS4s can minimize the amount of materials stored onsite, decreasing costs.