Washington State Department of Ecology

Best Management Practices (BMPs)
For Management and Disposal of Street Wastes


Site Inspection

Sampling and testing of all street waste solids is not needed to determine if it is dangerous (hazardous) waste since test data indicates that most street waste solids are not dangerous waste as defined by the state's Dangerous Waste Regulation, Chapter 173-303 WAC (Thomas, 1994). Street waste is solid waste and is regulated by the county health departments under the authority of the Department of Ecology. A site and waste inspection prior to collection of street waste is recommended to avoid mixing waste from the potential contaminated sites with cleaner waste.

If a site or waste exhibits unusual characteristics that would indicate excessive pollution, that waste should be left in place until tested for dangerous waste constituents. If an emergency requires the waste to be moved, the waste should be moved to a separate location and isolated from other waste until testing is completed. Preventative maintenance of stormwater facilities will help avoid emergency situations and reduce the needs and costs of additional testing.

Dangerous waste testing needs for street waste from suspect sites will depend on changes in the Dangerous Waste Rule. Likely tests will include: a fish or rat bioassay, PAHs, TCLP metals, and other suspected contaminants as directed by a Department of Ecology hazardous waste inspector. If testing shows that the waste is a dangerous waste, the solids and liquids must be handled and disposed of as a dangerous waste.

The Site Evaluation

There are three steps to a site evaluation:
  1. An historical review of the site for spills, previous contamination and nearby toxic cleanup sites and hazardous waste and materials storage nearby toxic cleanup sites and hazardous waste and materials storage,

    The historical review will be easier if done on an area wide basis prior to scheduling any waste collection. Records at the Department of Ecology office (see Appendix D) can help locate documented spills, toxic cleanup sites and hazardous waste and materials storage. The owner of the site should be contacted for records of previous contamination and the timing of the most recent cleaning. The historical review should be part of the bid process for private operators.

  2. an area visual inspection for potential contaminant sources such as a nearby fire, leaking tanks and electrical transformers, and surface stains,

    The area around the waste site should be evaluated for contaminant sources prior to collection of the waste. The area visual inspection may be done either as part of multiple or single site inspections. If a potential contaminant source is found, the waste collection must be delayed until the waste is sampled and found 'clean' or the potential contamination source is found to be not hazardous or to not have contributed to the waste being collected.

    A second portion of the area visual inspection is a subjective good housekeeping evaluation of the area. Locations with poor housekeeping commonly cut corners in less obvious places and should be inspected in greater detail for illegal dumping and other contamination spreading practices.

  3. and, a waste and container inspection before and during collection.

    The inspection of the waste and container is the last and most critical step in the site evaluation:

    For example, if the stormwater facility has an unusual color in or around it, then there is a strong possibility that something could have been dumped into it. Some colors to be particulary wary of are yellow-green from antifreeze dumping and black and/rainbow sheen from oil and/or grease dumping. Also, if any staining or corrosion is observed, then a solvent may have been dumped.

    Fumes are also good indicators of potential dangerous or hazardous waste. Deliberate smelling of catchbasins should be avoided for worker safety, but suspicous odors may be encountered from catchbasins thought to be safe. Some suspicious odors are rotten eggs (hydrogen sulfide is present), gasoline or diesel fumes, or solvent odors. If unusual odors are noted, contact a hazardous waste inspector before cleaning the basin.

Finally, operator experience is the best guide to avoid collection of contaminated waste.

Regular Testing

All street wastes must be sampled and tested for suspected contaminants on a regular basis by time or volume. The exact sampling frequency will depend on the volume of waste generated and needs of those receiving the waste, but should be at a minimum of once per quarter. This will help reevaluate this guidance in the future and provide certainty to those receiving the wastes.

Spills and Emergency Pickups

Call the local 24-hour Emergency Spill Response number which can be found in the community services section of your local phone book if a spill is witnessed. If possible to do safely, plug the stormwater facility inlet and locate the source of the spill to prevent any further discharge. Plugs are made for this purpose and should be carried on the vactor truck. It is advisable that street waste truck operators have hazardous materials training. Emergency pickups will usually not have the luxury of a site and waste inspection and must be stored seperately and tested for dangerous waste components or handled as dangerous waste.
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