P2 - Making a Real Difference at an Industrial Facility
Director of Environmental Operations and Affairs
Bruce R. Larsen
Project Manager, HDR Engineering
Valmont Industries, Inc. is an international manufacturing company engaged in the production of center pivot irrigation systems, light wall steel tubing, street and area light poles, traffic signal poles, communication structures and electrical transmission structures. The operations necessary to manufacture these end products generate solid and hazardous waste streams and air emissions. As our society has evolved, the way in which we view the wastes generated from industry and our everyday lives has changed dramatically. Through a combination of regulation and social consciousness, industry in the United States has moved from doing little or nothing in terms of waste disposal controls to treatment and now to minimization and prevention of waste generating activities. Not only does pollution prevention make good business sense, in many situations, it's also the law. This paper focuses on Valmont's pollution prevention activities and successes.
There are a number of reasons that Valmont has developed an approach and philosophy on pollution prevention activities; these reasons described in the following paragraphs are regulatory, economic, liability and human health and the environment.
Regulations have been developed for wastewater, air and solid wastes. The major emphasis or primary components for these pieces of legislation has been the reduction or elimination of pollutants. The goals of the Federal Water Pollution Control Act and the Clean Water Acts are to eliminate pollutant discharge to all waterways and to eliminate all toxic pollutant hazards. The National Pollutant Discharge Elimination System has been the primary cornerstone to achieve these goals. The Resource Conservation and Recovery Act and Hazardous and Solid Waste Amendments of 1984 mandated certifications by generators that the generation of hazardous wastes have been minimized and banned certain wastes from land disposal unless they can be demonstrated as not harmful to human health and the environment. The Pollution Prevention Act of 1990 is a federal act that requires facilities that report under the Toxic Release Inventory provisions of the Superfund Amendments Reauthorization Act to provide information on pollution prevention and recycling activities with each annual filing. The Clean Air Act requires state and local air pollution control agencies to adopt Federally approved control strategies to minimize air pollution. State Implementation Plans generally establish limits or work practice standards to minimize emissions of the criteria air pollutants. The result of these Federal and State laws in conjunction with societal concerns on siting of disposal facilities increases the cost of all waste treatment and disposal options and managerial work required to comply with these regulations.
Obviously, the biggest incentive for industry to reduce and minimize the amount of wastes and emissions that are generated is financial. Some sources indicate that the cost of managing waste escalates between 5 and 10 percent per year. Factors such as landfill closures and restrictions can have dramatic effects on disposal costs. Capitol and operating costs for treatment systems can comprise major outlays for companies. The reduction or elimination of these costs can in many cases increase a company's competitive advantage.
The combination of regulations and our court system has made liability a prime issue. RCRA, for example, holds a hazardous waste generator responsible for its wastes from "cradle to grave". In other words, once a business generates a hazardous waste, it's legally responsible for that waste forever. Additionally, in most cases, generators of hazardous waste are at least partially responsible for the cleanup of wastes that have leaked from disposal sites containing their waste. This financial responsibility can cost hazardous waste generators substantial sums of money. Generators using off-site treatment, storage or disposal face financial liability when the facility operators mismanage waste. Under the Comprehensive Environmental Response, Comprehensive and Liability Act's imminent and substantial endangerment provisions, a generator could be held financially responsible for the entire cleanup or restoration of a facility. Increases in insurance costs or an inability to obtain insurance can result in higher treatment and disposal costs.
Finally, the public has an increased awareness of the potential effects that hazardous waste and toxic pollutants can have on human health and the environment. Companies that actively work towards reducing their wastes and emissions can greatly improve their working relationship with the public.
Most companies now have an environmental policy stating their support for compliance with environmental laws and regulations. Valmont, too, has such a policy that is reinforced during annual training sessions and new employee orientation. However, Valmont has included in its environmental program establishing goals that are consistent with the company's environmental policy. Valmont has established short-term and long-term goals which are both quantitative and qualitative. The primary long-term goal is the elimination of activities which fall under regulations. To accomplish this long-term goal, short-term goals are established which are reviewed periodically. The short-term goals are developed during process reviews. Process reviews include criteria for reduction of exposure to government regulations and future risks. Ideas come from all levels of management and operations and all levels participate in teams seeking ways to improve. Examples of such cooperative arrangements are the elimination of the waste streams treated at the industrial wastewater treatment plant and thus the need for the IWTP and expanded powdercoat painting operations. In the case of the treatment plant, treatment operators who were the first to realize imbalances in the former system were the first to take action and participated in the solution. All operators were ensured of future employment baring unforeseen economic collapse and the information flow concerning the progress was maintained to reduce anxiety. Valmont is convinced that if minimization and prevention activities are to be successful, the support of the workers is required. The following examples demonstrate how this process has worked at Valmont.
Prior to the codification of the Clean Air Act (CAA); little thought was given to elimination of hazardous air pollutants and volatile organic compounds. Valmont, which customizes its products to meet the specifications of clients, would use the coatings specified as long as it could be applied economically and the resources were easily obtained. Prior to 1990, VOC emissions exceeded 100 tons annually and liquid painting of large transmission and light poles was standard operating procedure.
With the advent of the CAA of 1990 and the prospect of complying with maximum achievable control technology (MACT) requirements more attention was given to improving operating methods. Initially, the process review focused on the utilization of chemicals with fewer HAPs and VOCs, and ultimately the transition to a different technology. The goal was to reduce costs and exposure to the regulatory requirements. Through product substitutions and changes in product composition, emissions were brought under control and by 1993 actual emissions of both HAPs and VOCs fell below major source thresholds. Continued efforts included the transition to more powder coating in lieu of the traditional liquid spray operations. In 1996, total emissions for VOCs was 35 tons and for HAPs was 13 tons (the single largest HAP totaled 4.5 tons). This was from a facility with multiple process and sources for air emissions including 2 painting facilities, 2 galvanizing facilities, and a tire retreading operation.
In order to reduce VOC emissions, the methods employed were to identify all sources of emissions including maintenance activities, develop a computerized tracking system which built upon the existing purchasing system, working with suppliers to identify more environmentally friendly chemical substitutes, and obtaining "federally enforceable permit limits" as capitol improvements were made. The Valley location utilized 300 acres in its manufacturing operation and identifying all VOC sources was a significant undertaking. Departmental purchasing records were used to check operations records for sources with pre-existing requirements under construction permits. For other sources like maintenance, only purchasing records were used. Upon completion of this task, a computerized tracking system was developed which interfaces with material requisition and order (MRO) transactions and calculates emissions. The downside to this system is it is faster than real time use. Products are assumed to have been used at the time of the transaction. Therefore, emissions are slightly overestimated. The up side is all emissions are counted and operations are not required to guess at daily usage. Computer controls limit access to the system and though corrections can be made for unused material shipped as waste, for example, this system requires far fewer corrections than the previous operator input impact system.
Another tracking system Valmont developed for their purposes was waste tracking. Those two systems when used together can tell a more complete story. For example, a new pipe coating was implemented for a new customer which proved to be quite wasteful during operations. This was first discovered through the waste tracking system but far greater impacts could have resulted for air emissions. Because Valmont could quickly quantify the costs and results to various programs, timely action was taken to change the process and convert to more "friendly" chemicals.
Federally enforceable limits, though perhaps frustrating at times, are used to reduce and eliminate risk of more expensive regulations. Potential to emit values were reduced resulting in a Title V classification for the Valley, Nebraska facility of a Class 2 minor source. This was Valmont's goal after passage of the 1990 Clean Air Act. Realizing MACT standards and emission fees are costly, improved coating facilities were constructed and federally enforceable limits were sought through construction permits. This required education of all management levels within Valmont to implement and employ.
The "people" factor is the most useful and most volatile portion of the program. Continued training and awareness programs are used to remind existing operators of the need to minimize and educate new employees and recycled workers. Valmont has historically promoted and re-assigned employees to different departments and divisions. These employees must be re-trained on how to look for minimization and pollution prevention opportunities in their new positions.
During the galvanizing process, product material undergoes a pickling process. The pickling process involves immersing product material through a series of tanks to clean and prepare the material prior to immersion in a molten zinc bath. The first step is the caustic tank where oils and greases are removed. Next, the material is transferred to an acid tank containing a 10% sulfuric acid solution. The "pickling process" removes oxidized iron from the surface of the product. Next, the material is transferred to an acid rinse tank where residual sulfuric acid is removed. The final step prior to the zinc kettle is the flux tank where the surface of the steel is prepared so that the molten zinc will bond with of the steel.
Two major sources of wastewater were generated from the galvanizing process: waste acid and acidic rinse water. Waste acid was generated as a result of a build up of iron and other impurities in the acid which greatly reduced its effectiveness for pickling. Once an acid bath was spent, it was discharged to one of two 25,000 gallon holding tanks. From these tanks, it was transferred to the industrial wastewater treatment plant where the spent acid was treated with a calcium hydroxide solution. Treated effluent was then combined with the acid rinse water for treatment and discharge and the sludge was dewatered and landfilled. The combined waste stream was approximately 20-25 gpm. Annual labor, chemical and disposal costs were approximately $500,000. Because of the costs and difficulties associated with treatment and disposal of spent acid, acid recovery was one of the first areas targeted for pollution prevention.
Valmont reviewed several commercial systems for recovery of sulfuric acid from spent pickle liquor. These systems rely on the crystallization of iron salts from the spent pickle liquor. The acid recovery system utilized by Valmont cools the waste acid so that ferrous and zinc sulfate heptahydrate is crystallized from the solution. The crystals are then separated from the regenerated pickling liquor stream by a centrifuge. The crystals are non-hazardous, light blue in color and are being sold for metals recovery. Valmont stopped treating spent pickling liquor in its wastewater treatment plant in December 1992.
The second source of wastewater was the continuous discharge of rinse water. Rinse waters from the galvanizing process were acidic and contained low concentrations of metals. Rinse flows were continuously discharged to an industrial wastewater treatment plant (IWTP) at a rate of approximately 15 gallons per minute. The IWTP consisted of flow equalization, pH adjustment, flocculation, clarification, sand filtration and final pH adjustment. Sludge from the process was dewatered using a plate and frame filter press and disposed of in a local municipal landfill. In the three years prior to discontinuing the treatment of acid, approximately 2,500 tons of sludge was landfilled annually. Treated effluent was then discharged through a permitted NPDES outfall. Major annual costs for wastewater treatment included operating labor, supervision, maintenance, general plant overhead, chemical costs, sludge disposal costs, utilities and regulatory reporting. Following the installation of the ARS and the associated realizations of cost savings, Valmont employees began to investigate alternatives for reducing costs for treating the rinse waters. Initial investigations centered on minimizing or reducing the amount of rinse water being treated at the IWTP. Wastewater treatment operators worked closely with the process personnel to understand the operation and reduce the amount of rinse being used. Rinsing is used to dilute the concentration of contaminants adhering to the surface of the workpiece to an acceptable level before the workpiece passes onto the next step in the galvanizing operation. Initially, Valmont employees were successful in reducing the volume discharged to the IWTP. However, by utilizing the fact that the rinse baths were heated to 150ºF to 160ºF, the wastewater and galvanizing personnel were able to devise a countercurrent rinsing system. In this system, each workpiece is rinsed following descaling in an acid tank. The rinse tanks are arranged in a series and the product is lowered into each rinse tank. The tanks contain progressively cleaner water, with the makeup water being added to the cleanest tank. A float valve has been added to the last tank which contains the dirtiest rinse water. As the water in the rinse tanks evaporates, the float valve signals for more water which is added to the cleanest tank. This tank is the last stage in the rinsing operation and contains the cleanest water. In order to prevent contaminants from building up in the first rinse tank, water is periodically used to dilute the concentrated acid used in the pickling operation. By implementing this operation, all flow to the IWTP has been stopped and the treatment equipment has been moth-balled. Over a period of approximately five years, Valmont was able to eliminate its wastewater discharge. The wastewater treatment operators have been reassigned to other duties in the manufacturing operation.
Waste Management Programs
Another successful program for Valmont has been the "partnering" relationships with vendors. National contracts for hazardous waste disposal has resulted in decreased costs; limited the number of disposal locations from a risk/liability management prospective; and allowed us to take advantage of vendor expertise improve operations. Standard contracts for materials and non-regulated wastes also reduce future risk and ensure that commitments are maintained.
These efforts do not and have not replaced the need for individual manufacturing units to realize the need for process controls and waste minimization. Waste disposal expenses are funneled back to the operating divisions and departmental waste generation is tracked. Regular meetings with departments generating waste are held to inform them of their status and dollars spent. As a result, design engineers are now aware of the need for interfacing with the environmental coordinators which in turn has led to more effective internal communications. Again, the development and utilization of the waste tracking system has made reaction to processes that emit or generate excessive wastes more timely and efficiently. Marketing is more aware of concerns with coatings applied to our products and teams work with customers to change specifications to produce more environmentally friendly products. For example, when a customer orders a product that requires a liquid coating, a secondary team contacts the client in an effort to demonstrate the virtues of power paint which have lower VOC emissions. Processes have also been added to reduce waste generation including purchasing and fabrication. New chemicals require approval by the environmental coordinators before they can be added to our chemical inventory and used.
Valmont's efforts in waste minimization and pollution prevention have been greatly rewarded. Workers, when informed and treated as part of the team, generally perform well and take ownership of their operations. They operate within specifications and requirements, feel empowered to discuss ideas that reduce and prevent waste generation and work within the system. This results in overall compliance with rules and regulations, improves discussions, reduces quality issues, reduces the amount of waste generated, provides greater morale and benefits the environment and the company's profitability.