Storm Water Control & Compliance

Protection of our surface water and groundwater resources is a primary objective of federal and state environmental regulations. Toward this end, the federal government implemented regulations to control the impacts from infrastructural development and commercial and industrial activities. Many of these regulations were emplaced with the Federal Water Pollution Control Act Amendments of 1972 and its amendments in 1977, commonly known as the Clean Water Act of 1976. The Clean Water Act established the basic structure for regulating discharges of pollutants into the waters of the United States, implemented as National Pollution Discharge Elimination System permits. Subsequent modifications and additions to the Clean Water Act by both federal and state governments have increased the requirements of facilities to meet storm water quality goals.

ENW specialists seek to help clients meet the regulatory requirements in an efficient, economical way. We approach storm water management from the perspective of total facility environmental planning. If contaminants can be prevented or inhibited from coming into contact with storm water run-off by implementation of generic and site-specific Best Management Practices (BMPs), then the client’s compliance burden is lessened, and the need for engineered solutions with associated costs are reduced. Where engineered solutions are required, ENW can design and construct mitigation features such as retention ponds, infiltration galleries, settling ponds, engineered wetlands, catch basins, oil-water separators, secondary containment, and filtration media.

ENW can also help clients meet the required monitoring and submittal schedules required under NPDES permits. Our field technicians are well equipped to perform field parameter determinations and collect analytical samples specified in NPDES permits with minimal disruption to business activities.


Metal Recycling Facility Multnomah County, Oregon

As a result of EPA’s approval of the Oregon Department of Environmental Quality’s TMDL strategy for the Columbia Slough watershed, all facilities discharging to the watershed were combined into a single permit. ENW developed and implemented a Storm Water Pollution Control Plan (SWPCP) to minimize releases of pollutants to surface water from the facility’s scrap metal recycling operations. The goal of the SWPCP was to meet benchmarks for specific chemicals of concern, which would indicate that the site had successfully reduced pollutant concentrations to standards consistent with the collective NPDES permit.

Lumber Mill and Retailer Clark County, Washington

Storm water from this site discharges under a National Pollutant Discharge Elimination System (NPDES) General Permit. A requirement of the permit was the preparation and implementation of a Storm Water Pollution Prevention Plan (SWPPP). ENW evaluated the pervious and impervious areas of the site and the industrial activities that occur in the many structures at the site. Based on the findings, ENW developed the SWPPP plan in accord with the requirements of the Washington Department of Ecology.  

Medical Facility Multnomah County, Oregon

The storm water disposal system at this major medical facility consists of a complex network of dry wells and infiltration galleries. ENW prepared a Storm Water Pollution Control Plan (SWPCP) for the storm water collection system and an Underground Injection Control (UIC) rule authorization application for the underground injection disposal system. ENW investigated historical facility, city, and county records to map out the subsurface drainage system. Based on these findings, ENW completed SWPCP, UIC, and Spill Prevention, Control, and Countermeasure Plan documents for submittal to the Oregon Department of Environmental Quality.