November/December 2010
There’s no one-size-fits-all solution for scrapyard stormwater control. Each facility’s pollution prevention plan will be a unique combination of practices and physical controls.
By Chelan David
Water, water everywhere. That’s the frustration of scrapyard managers facing increasingly stringent stormwater regulations. Whether it comes in the form of a drizzle or a hurricane, the water falls from the sky onto scrap and equipment in the yard, washing tiny particles of metal, oil, and other contaminants into the surface water. This was just a fact of life until about 20 years ago, when the U.S. Environmental Protection Agency (Washington, D.C.) and state environmental agencies first established stormwater permits that require recyclers to monitor and control what’s in the stormwater runoff from their facilities.
Scrapyards can face steep obstacles in meeting permit requirements. First, the core of many scrap recyclers’ businesses is processing the same metals that most industrial stormwater permits regulate. Capital costs are another possible hurdle. Expenses associated with engineering and design work, site grading, hard surfacing, and the construction of covered or indoor storage, outdoor containment areas, treatment systems, and water collection points such as stormwater ponds can be prohibitive for some recyclers. Then there are what Larry Berndt, principal of Wenck Associates (Woodbury, Minn.), terms “legacy issues”: a scrapyard that’s near or adjacent to “vulnerable waters or other receptors,” or where the ground is already contaminated by years or decades of use as an industrial facility prior to the existence of environmental regulations.
Over the years, allowable pollutant loads have fallen and the consequences for failing to comply have grown. Recyclers whose discharges exceed allowable thresholds may face a range of potential penalties. The EPA or state agency might send a warning letter, followed by fines for continuing violations. In some cases, the agency can make the offending facility switch from a general permit to an individual permit, which is more expensive to implement and imposes more specific limits and mandates.
Facilities that are not in compliance can end up in court, where employees might even face criminal sanctions for knowing or negligent discharges. Even a simple warning letter could be problematic for yards that have suppliers that audit recyclers for environmental compliance. Stormwater permit holders also can face third-party litigation, which is almost always more expensive than agency enforcement actions. Citizen suits can result in substantial penalties that have bankrupted more than one company. The negative publicity that can accompany such a suit is damaging in itself. The longer problems persist, the more likely it is that the media or environmental groups will publicize the issue.
Ironically, a facility’s attempts to come into compliance can draw negative attention. If a facility does not meet its benchmark monitoring criteria, it must review its best management practices and revise them—or implement new ones—as necessary. Typically, if a facility is in the process of evaluating and improving its stormwater BMPs, it can avoid fines. But the data it submits to regulatory agencies is generally public information, thus environmental groups or other concerned parties can access it and launch a third-party lawsuit anyway.
Who’s Regulating What
The EPA sets the benchmarks for the federal multisector general stormwater permit that governs certain industrial facilities in some American Indian lands, federal facilities, U.S. territories, and four states: Idaho, Massachusetts, New Hampshire, and New Mexico. All other states have the authority to establish their own benchmarks, which the central state environmental agency—often a state EPA—typically handles.
Most industrial stormwater permits restrict the discharge of suspended solids, oil and grease, and metals, including copper, lead, and zinc, and they set parameters for the water’s pH level, which is a measure of its acidity. Certain states require monitoring for other metals such as aluminum, iron, or cadmium; nutrients such as phosphorus; and reporting of parameters such as chemical oxygen demand, which is a measure of organic pollutants. “In general, the metals of greatest concern include copper and zinc, both of which exhibit toxicity effects to aquatic organisms, and lead, which has proven to be a human toxin,” says Calvin Noling, president of StormwateRx (Portland, Ore.).
Some permits require the facility to submit a chemical analysis to the appropriate regulatory authority; others have the facility complete the analysis and keep the results on site and accessible if or when the regulatory authority requests the data. In nearly all cases, the facility must have a stormwater pollution prevention plan on site. Such a plan typically presents various structural and nonstructural BMPs the company will implement and maintain to meet regulatory thresholds, Berndt says. Nonstructural components are activities the company undertakes to control stormwater pollutants, which might include general housekeeping (including facility sweeping), assigning employee responsibilities, performing site inspections, and having spill response and cleanup plans, he explains. BMPs for structural components address the construction, operation, and maintenance of aspects of the physical plant, such as containment pads for scrap storage, indoor facilities, covered structures, stormwater ponds, and site grading.
Effective BMPs should include strategies to control, segregate, and treat stormwater pollution, Noling says. Physical controls might be a matter of reorganizing the yard setup so the stormwater moves more rapidly out of the yard and away from pollutant sources. Paving, temporary covers for bales or containers of scrap, bunkers for various types of scrap, ribbon drains, catch basins, and storm drainage piping are some other physical controls of stormwater. Yard sweeping also is very effective at reducing the amount of pollutants that rainfall can wash away. For segregation, yards can use curbs and ribbon drains to collect runoff at the point of generation. This keeps it away from dirtier stormwater in high-use areas and prevents it from contaminating cleaner stormwater runoff. Segregation also is helpful for facilities that process turnings, borings, or stampings that contain cutting oil. Ideally, the yard should store those materials under cover or indoors, Noling says. Turnings, borings, and stampings stored outdoors should drain to a segregated sump to keep the oil from entering the general stormwater stream.
Treatment Options
Companies that offer stormwater treatment systems attack the problem in different ways. StormwateRx provides three basic levels of stormwater treatment, Noling says: basic treatment (gravity separation), enhanced treatment (filtration), and advanced treatment (polishing). The levels build on each other; thus a yard might require one, two, or all three levels of treatment to reach its discharge quality needs. Using treatment BMPs in series conventionally is known as a “treatment train.”
Basic treatment, or gravity separation, uses gravity to separate pollutants from the stormwater. Gravity separation mechanisms include detention ponds and stormwater vaults. A pond might not look like it’s doing anything, but it reduces the water velocity so heavy dirt particles settle to the bottom. Vaults or ponds with skimmers provide the added benefit of free-floating oil removal. Ponds and vaults both must be cleaned out periodically to remove accumulated oil and sediment.
In filtration treatment of stormwater pollution, the filter medium traps small particles and associated metals and solids the stormwater is carrying. Enhanced filtration systems are robust mechanical systems that have special filter media that remove dissolved metals. Most scrap facilities should choose a filtration system designed for heavy particulate loads and pay careful attention to filter wear. Though catch basin insert filters are an important part of most stormwater pollution control strategies, they are regarded as source control BMPs rather than treatment BMPs as discussed here. “For industrial stormwater applications, filters that have been in service for a few storms can produce better water quality results than new filters because the trapped dirt particles help do some of the filtering,” Noling says, but “over time, pollutants build up within the filter media, reducing the throughput.” To keep the system functioning at that point, someone must remove the pollutants from the filter (through backwashing or scraping, for example) or replace the spent media with new media, he says.
Advanced treatment, or polishing, technologies can bring stormwater to clean water standards for reuse as process make-up water or for the most protective discharge to groundwater or surface water. The techniques depend on the specific kinds of pollutants the facility generates and its discharge quality needs. Options include disinfection for bacteria reduction, ion exchange technologies to remove dissolved metals to low levels, and surface filtration to remove fine particles from the stormwater. To achieve that level of pollutant control, polishing systems require relatively clear inlet water; thus they most likely follow filtration or other pretreatment.
Taking a different approach is WaterTectonics (Everett, Wash.). Its WaveIonics system uses electro-coagulation to remove most pollutants from the stormwater. “Instead of using chemicals to create a coagulation reaction, we use electro-coagulation cells,” explains T.J. Mothersbaugh, the company’s industrial sales manager. The system has an anode and a cathode attached to a series of metal plates. The electrical charge releases an ion off of the anode and gas off of the cathode to facilitate the release and separation of pollutants from the water. “We think of it as the heavy hammer,” Mothersbaugh says. Electro-coagulation “will go after turbidity, metals, oil and grease, and even bacteria in some applications.” The company offers systems that can treat from 50 to 1,000 gallons a minute, though its 100 gpm and 300 gpm systems are the most popular.
The WaveIonics system arrives in a shipping container with all the treatment components mounted inside. The water enters the box, goes through the EC treatment cells, and then moves into a settling tank or vault at the client’s site. After settling, the water returns into the system and goes through a sand filter “as a final step to capture any remaining solids, then it goes through a water quality valve to check for turbidity and pH,” Mothersbaugh says. If the water has not reached a predetermined range of measurements that indicate it’s acceptable for discharge, it cycles back through the system. The control cabinet has a monitor with a touch-screen user interface that provides real-time information on water quality, including turbidity, conductivity, and pH. The company also sells systems for just oil and water separation.
System Design Variables
A scrapyard’s stormwater control needs will vary according to the type of scrap it processes, the stormwater discharge location (where the water goes after it rains), and its land use and drainage, not to mention the requirements of the local, state, and/or federal regulatory authority. In terms of scrap commodity, it should be no surprise that ferrous scrap recycling facilities tend to produce runoff that’s high in iron, though other metals typically are present in lower concentrations. Other metals such as zinc and copper tend to be present at these facilities as well because ferrous and nonferrous scrap may be produced from the same feedstock and because processing equipment and exposed scrap release these metals. Such facilities will require basic treatment and, in some cases, enhanced filtration treatment. Nonferrous metals such as copper, lead, and zinc can be more problematic because they can be more toxic to aquatic organisms; thus state and federal regulators often have more stringent benchmark thresholds for them. Facilities that process metal turnings, borings, or stampings have to contend with emulsified oil in runoff, which is particularly difficult to remove.
Discharge location comes into play in the design of a scrapyard’s stormwater treatment system because discharges to water bodies that already exceed ambient water quality standards face stricter discharge levels. For example, Noling says, if the concentration of copper in the receiving water is already over the allowable ambient water quality standard, the regulatory agency might prohibit any new discharges of copper and limit all copper discharges to the water quality criterion—which is lower than the copper benchmark—at the end of the pipe. “Impaired water quality is most common in highly industrialized areas and on small streams,” Noling says. “Discharges to exceptionally clean water bodies may also need to meet strict limits to protect the high quality of the water and its uses. In most cases, only advanced treatment can meet these water quality requirements.” Infiltration to the groundwater, if allowed, is an attractive option for some yards because it reduces the amount of runoff. Direct infiltration without some form of basic or enhanced treatment, however, is not advisable because of potential groundwater contamination issues or because legacy soil contamination at the site might be mobilized to the groundwater.
Land use and drainage come into play because stormwater moves more slowly across flat land and picks up fewer pollutants. Unpaved recycling yards in particular and those without storm drainage systems are problematic from a stormwater quality perspective because movement of heavy equipment and vehicle traffic on the land surface exacerbate erosion and scrap metal sits in puddles of stormwater. Having a paved yard or one in which equipment operation is restricted to higher ground could make it easier and less expensive to implement a stormwater pollutant control system. Erosion contributes tremendous amounts of suspended solids to stormwater, while scrap metal sitting in puddles adds dissolved metals to the stormwater. Ideally, Noling says, even facilities on flat land should pave their yards “and install stormwater catch basins and ribbon drains to keep the water off the operating surface.”
Another important goal for stormwater treatment systems is to design them “offline.” That is, there should always be a means to allow a portion of the stormwater to bypass treatment if the storm event is larger than the system’s designed capacity. Basic treatment ponds and vaults should include an internal or external high-flow bypass; otherwise, pollutants will be washed out when a large storm occurs. Enhanced and advanced treatment systems inherently are designed with this bypass principal in mind since water typically is pumped to these systems at the design flow rate. Any stormwater exceeding the pump capacity will bypass through the pump vault.
Installation and Maintenance Costs
The costs associated with stormwater systems vary depending on the type of treatment system, the necessary treatment performance, the quantity of rainfall the yard receives, yard size, and the type of recycling the yard conducts, though companies that construct and install such systems size and configure the systems based on jurisdictional requirements (if any) and experience with similar installations. WaterTectonics’ systems start around $175,000. Often clients purchase the system as part of a bigger capital project, Mothersbaugh says; thus the company works with engineers and contractors to fit the system to the site from a logistics and operational standpoint. WaterTectonics’ installation team hooks the system to the aboveground plumbing, and the client’s electrician connects it to the power supply.
For StormwateRx, the capital cost for basic treatment, or gravity separation vaults, ranges from $2,000 to $5,000 per acre drained, Noling says. Installation is roughly 50 percent of the capital cost, and the annual maintenance—removal of accumulated sludge and floatables—is roughly 5 percent of the capital cost, he adds. Capital cost for ponds largely is driven by land cost, though some jurisdictions may require a liner, which adds significantly to the cost. Maintenance of a basic system typically requires a vactor truck (for vaults and lined ponds) or excavator (for unlined ponds). Properly sized enhanced filtration can be $20,000 to $80,000 per acre. Installation is roughly 30 percent of the capital cost, and annual maintenance is approximately 2 percent to 5 percent of the capital cost. Advanced treatment, or polishing, expenses are site and pollutant specific, he says.
One factor that can add to the cost of the StormwateRx system is the need for electricity at the treatment site. “Basic treatment, or gravity separation, typically does not require electricity, provided sufficient depth is available in the existing drainage system at the discharge point,” Noling says. Conversely, “enhanced treatment or filtration typically cannot be implemented on a retrofit basis at most sites without pumping. Because of that, siting of the filtration system near available power can help keep the installation cost down.” Advanced treatment systems also require power and “are usually pressurized vessels with a small footprint.”
For ongoing operations and maintenance, WaterTectonics trains one or two of the scrapyard’s workers. “We take them through a 40-hour training course, with hands-on training, then they operate on their own,” Mothersbaugh says. “It operates pretty much automatically, with an alert system.” Maintenance might entail cleaning and replacing treatment cells or filter media, calibrating discharge quality probes, cleaning sludge out of settling tanks, and replacing pH-adjustment chemicals and other consumables, he says.
Upstate Shredding recently installed a stormwater system from Alar Engineering Corp. (Mokena, Ill.), a wastewater treatment systems manufacturer. The company custom-designed the system to control heavy metals and oil solvents. A water tank on site collects stormwater runoff, grease, and oils from the shredder. Using sump pumps, the system transfers the water to a holding tank where it’s treated with an acidic chemical and lime. “Once treated, [the water] gets transferred to the filtration holding tank,” says Adam Weitsman, Upstate Shredding’s president. “For about an hour-and-a-half cycle, the filtration tank will pump the water [through] the filter. Then it goes out to the sewer.” The project—including yard paving—cost $2 million. Maintenance expenses are minimal, he adds, as employees at the facility clean and empty the filters.
Selecting a Stormwater System Vendor
Calbag Metals (Portland, Ore.) installed its first stormwater system in 2003 after it began to consistently exceed its benchmark levels for metals in sampling tests. The initial system was a StormFilter from Stormwater Management (Portland, Ore.). (The company later was acquired by Contech and renamed Contech Stormwater Solutions.) The stormwater passed through two chambers containing cartridges filled with filtration media to capture copper, lead, zinc, oil, and grease. In 2009, the company switched to an Aquip enhanced sand filter from StormwateRx designed to control solids, the abovementioned metals, and oil and grease. “Prior to installation of the StormwateRx system, we were unable to stay below benchmarks on copper despite a very aggressive program of BMPs,” says Chuck Gleason, Calbag’s director of operations. “Since the system was installed, we’ve had no exceedances.” The system, which serves about 2.5 acres of land, cost about $150,000, and the annual maintenance is about $18,000, he says.
Gleason advises scrapyards looking to invest in a stormwater system to make sure the vendor has a proven ability to reduce comparable contaminant loads to benchmark levels. WaterTectonics’ Mothersbaugh concurs. “Scrapyard operators should look closely at a vendor’s previous experiences and make sure they match the yard’s needs,” he says. “Speak with a vendor about visiting an installation at a comparable scrapyard. It’s a good opportunity to see an installation in person and speak with an operator who has lived with a system day in and day out.” His company has systems at four scrapyards, including a few shredder yards, and expects to install a fifth in a few months.
A common-sense approach to stormwater management will go a long way toward compliance, Berndt says. “Don’t be fooled by systems that claim to take your problems away,” he says. “No matter what type of system is installed, proper site maintenance, implementation of BMPs, and good housekeeping are prerequisites to success. Look for proven methods of stormwater treatment,” and make sure you can adapt your system to future regulatory changes.
Chelan David is a writer based in Overland Park, Kan.
There’s no one-size-fits-all solution for scrapyard stormwater control. Each facility’s pollution prevention plan will be a unique combination of practices and physical controls.