November/December 1991
New, stricter storm water regulations may require some scrap operations to install advanced treatment systems and make significant investments in remediation. Here’s how one company tackled the problem.
By Ralph Miller and Norman D. Webb
Ralph Miller is president of the MMI Group (Portland, Ore.) and its subsidiaries, including General Metals of Tacoma Inc. (Tacoma, Wash.). Norman D. Webb is assistant to the president and environmental manager of the MMI Group.
Water, water, everywhere,And how the boards did shrink;Water,water, everywhere Nor any drop to drink.
These lines from Samuel Taylor Coleridge's "Rime of the Ancient Mariner" might have inspired recent federal legislation that could seriously affect many in the scrap recycling industry in 1991 and beyond. Reauthorization of the Clean Water Act led to Environmental Protection Agency (EPA) regulations that require all industrial facilities, including scrap processing and recycling plants (which are specifically mentioned in the rule), that discharge storm water through a "point source" into a municipal storm sewer, private treatment works, or surface water body to file applications to obtain National Pollutant Discharge Elimination System (NPDES) permits. The EPA will review the applications and, in conjunction with EPA regional offices and state agencies, develop storm water management plans for all applicants.
For some, implementing the plan mandated could require a major investment of time and money. General Metals of Tacoma Inc. (GMT), a Tacoma, Wash., ferrous scrap processor, began implementing a storm water management plan in 1987 as part of a state-mandated site cleanup. The entire cleanup required not only a storm water drainage and treatment system, but also removal of contaminated soil and sitewide paving of the 26-acre, partially paved plant.
When the entire storm water system is completed in the summer of 1995, it will include sitewide drainage and four storm water storage tanks that will feed into the treatment facility, which includes oil/water separation and liquid/solid separation. GMT expects to spend a total of approximately $10 million on its compliance project, including consulting and engineering services, laboratory work, paving, soil removal, and construction of the drain system and water treatment plant.
This project is a much bigger undertaking than the NPDES storm water permit requirements most scrap processors and recyclers will be subject to, but represents a potential scenario that could become reality for some industry members.
The Way It Happened
It all started in December 1986, when GMT was inspected by the Washington Department of Ecology. GMT is located on the northeast side of the Tacoma tidal flats of Commencement Bay--a Superfund site--and was inspected as part of the department's source-control activities that must be conducted before dredging of the Superfund site's waterways can begin. The inspection centered around sampling of the company's soil and surface water, which revealed elevated concentrations of the following contaminants and heavy metals: total suspended solids, oil and grease, polychlorinated biphenyls (PCBs), arsenic, cadmium, chromium, copper, lead, mercury, nickel, and zinc.
The department then ordered GMT to collect and contain surface water on an interim basis to prevent soil particles from moving via storm water runoff and further contaminating the on-site surface water. In addition, the department mandated that the company conduct a remedial investigation/ feasibility study to determine the scope of the contamination and propose corrective actions, which included removal of contaminated soil and installation of sitewide drainage and paving. The study also provided data that were included in a state-ordered treatability study to determine how the contaminated surface water could be treated prior to discharge from the site.
Gathering Data and Drafting Plans
The treatability study was conducted in four phases to obtain sufficient data to fully evaluate GMT's storm water treatment options and to properly design an on-site treatment system.
Examination of Storm Water Runoff. The study sought to identify the contaminants in the storm water, specify all drainage areas, calculate flow rates and the storm water storage required for each area, and develop storm hydrographs for each drainage area based on a 10-year storm event of 2.9 inches in 24 hours. A storm event refers to the severity of a storm; a 10-year storm event means that a rainfall of a particular severity (in this instance, 2.9 inches in 24 hours) comes along approximately every 10 years. The higher the storm event rating a company must meet, the more water storage capacity the company must have on-site. The Department of Ecology initially requested a 25-year storm event rating, while GMT proposed a 2-year rating. The two parties eventually agreed to use a 5-year storm event rating of 2.5 inches in 24 hours in the final system plans.
Collection of Storm Water Samples. Samples were collected from sumps, specially installed weirs, and selected other locations to obtain representative results The samples were collected within the first hour after the start of a storm to represent the worst-case contamination and at the end of the runoff to represent the best-case contamination.
Bench Tests. GMT's environmental consultant, its subcontractors, and selected equipment and chemical vendors conducted small-scale bench, or laboratory, tests designed to determine how the contaminants flow at the site and what chemicals or processes could be used to treat the water to meet government standards.
Pilot Tests. The results of the bench tests identified the most promising treatment methods, the best one of which was further evaluated using a vendor-supplied pilot unit at the GMT site. This step--going from laboratory to practice--focused on reducing the contaminants in the storm water as much as possible, while also holding down system costs.
Following completion of the treatability study, GMT prepared a draft engineering report for the Department of Ecology's review. This report described the treatability study's results in detail and reviewed the proposed treatment system technologies: a basic surface-skimming process for oil/water separation and a more advanced laminar-flow clarifier to handle liquid/solid separation. (In the clarifier, chemicals and polymers help to promote settling of solids in the water, enabling GMT to meet its treatment standards.)
Once approved by the department, the engineering report became the basis for draft system plans and specifications that were also submitted to the department for approval.
Applying for Permits
While the engineering report was being prepared and approved, GMT applied for the permits necessary to construct and operate the storm water drainage and treatment systems. Because part of the plant is located within 200 feet of the Hylebos Waterway, GMT had to obtain a shoreline permit under Washington's Shoreline Management Act of 1971. The application was subject to public hearing; approval by the Tacoma City Council; review by various local, state, and federal agencies; and final approval by the Department of Ecology. Separate permits were also required from the U. S. Army Corps of Engineers and the Washington Department of Fisheries.
The most critical permit, of course, was the NPDES permit. The conditions of this permit, issued by the Department of Ecology, required the storm water treatment system to meet strict effluent limitations-derived from the treatability study test results--at the system's clarifier output, the point at which treated storm water is discharged. The permit also requires samples taken at the perimeter of the mixing zone--the area in which the treated storm water is dispersed into the Hylebos Waterway--to meet state water quality standards. As of this writing, however, it is not known if water at the edge of the mixing zone will meet this requirement.
The NPDES permit also requires monthly operating reports, a spill prevention plan, a solid waste control plan, a sediment monitoring study, a chemical analysis, a mixing study, an operation plan, and biomonitoring.
Selecting the Right Equipment
Once the permit requirement and system technology needs were established, it was time to start implementing the plans through equipment purchase and installation. GMT's consultants identified seven manufacturers of water treatment equipment for evaluation, each of which was sent a detailed request for quotation (RFQ) based on a specific treatment system plan identified by the earlier engineering report. The manufacturers were also invited to submit proposals for alternate systems that they believed could do a better job and/or would be less expensive than the one described in the RFQ.
GMT's final system selection criteria included equipment lead time (the Department of Ecology wanted the system installed as soon as possible), performance warranties, initial capital cost, and ongoing operational costs. The winning bidder received a purchase order--which required that one of the manufacturer's engineers be on-site for three days during system startup and train GMT's personnel--and immediately began to prepare the final plans and specifications for submission to the department for final approval. The treatment facility was delivered and installed with minimal problems in the first quarter of 1991 and is now operational.
Taking an Active Approach
While the GMT experience involved both storm water treatment and site remediation spurred by the company's location within a giant Superfund site, it is not unreasonable to expect that other scrap metal recycling plants could have similar experiences stemming from new compliance programs such as NPDES permit requirements. Many scrap facilities may be plagued by the site damage of previously acceptable practices that will have to be remediated.
Land owners and operators of scrap processing and recycling businesses should act promptly to assess the environmental condition of their sites and develop a plan that will lead to remediation, if necessary, without destroying the business.
Taking an active role in the process, including working with regulatory agencies, is often the least costly approach and may help you retain more control than you might otherwise be offered if storm water treatment and other remediation measures are required. Site cleanups that are unilaterally ordered and/or executed by regulatory agencies usually result in little or no control over the nature and extent of the investigation, the selected solutions, or the schedule of implementation.
The best first step to an active approach is to retain the services of an experienced environmental attorney and consultant. Though expensive, these environmental experts can play a vital role in identifying and implementing a viable solution to your environmental needs. •
New, stricter storm water regulations may require some scrap operations to install advanced treatment systems and make significant investments in remediation. Here’s how one company tackled the problem.