Moving Toward the Zero Discharge Goal
A highly desirable “state” for environmental protection would be Zero Discharge of pollutants to the air, water, and land. Today, this is a goal not yet realized. However, “approaching” Zero Discharge has been found to be realistic, as demonstrated by the continual improvement in environmental performance achieved in the SGP for the metal‐finishing sector. Approaching Zero Discharge can be defined as reducing wastes emitted from a process by a significant amount, with significant reduction ranging from a low defined by the regulatory standard and the high defined by the technology employed.
There are two key elements to achieving movement toward the state of Zero Discharge – implementation of an EMS and deployment of certain technologies based upon pollution prevention. The framework of an EMS is the management tool that provides a state of “continuous assessment and compliance of plant operations,” while P2 technologies provide the technological tools needed to achieve significant improvements in performance and reductions in generation of waste.
Planning and Implementation
As part of the planning phase, a compliance assessment of a participating plant is necessary to establish a baseline against which progress and savings in incremental costs can be measured. The goal of the plant assessment is to identify the root causes of the most significant problems, to identify areas in which P2 options could save the most money, and to assign priorities to address the most significant problems. The plant assessment must include an inventory of all chemicals, wastes, bath chemistries; the overall plant layout; and a site inspection. Once the problems are identified and prioritized, various solutions can be proposed and the effects of their deployment evaluated. A comprehensive plan addresses housekeeping and maintenance issues in order to sustain any P2 efforts and also to establish good standard practice.
This planning approach is most efficiently implemented through an EMS. In addition, the imperatives of “total quality management” apply. Management must buy into the process and be willing to provide the necessary resources to achieve success. Experience has shown that often the best solutions come from those working most closely to the problem. It is important that employees be included in the improvement program and kept well informed so that they will become stakeholders in the process.
Implementation through an EMS has several advantages. First it is more effective because it provides a tool for involving management through its provision for continuous improvement in both environmental performance and worker health and safety. Second, it provides a mechanism to integrate process and product quality issues that influence reduction of waste and the improvement of productivity and profitability. The review of these considerations should be incorporated into the process and reviewed over time as a pathway for identifying future opportunities and establishing priorities. This process leads to the identification of the power of pollution prevention technologies to achieve these savings offered by waste reduction. The Agency provides an EMS template tool (USEPA 2004; Stander and Theodore 2008) to assist those who are interested.
Many of the same elements that must be defined for the compliance assessment are also needed to establish an EMS. Certification under the ISO 14001 – an EMS that is standardized worldwide – is being increasingly required of those companies engaged in the manufacture of products for export, including components in the supply chain of such products. Also the EPA offers Compliance Incentives – “policies and programs that eliminate, reduce, or waive penalties under certain conditions for business, industry, and government facilities which voluntarily discover, promptly disclose, and expeditiously correct environmental problems” and is including a requirement for the implementation of EMSs in settlements. Information about these incentives, programs, and the environmental benefits achieved by such programs may be found on the Internet (http://www.epa.gov/compliance/incentives/index.html).
Practicing Pollution Prevention
Technologies based on the precept of Pollution Prevention serve to eliminate the generation of wastes or to reduce the disposal of wastes through recycle/reuse. Pollution in the metal‐finishing industry is basically the discharge of some unwanted form of material or other resource (energy, labor, time, etc.). Loss of these resources equates to the loss of profit and economic productivity. It stands to reason that the more of a resource used above the minimum required by the process, the more this incremental use (read: “waste”) adds to the “unnecessary” component of the total costs of the operation. In the case of water use, for example, this unnecessary cost is not just the cost of the excess water wasted. The cost of this waste is magnified by the costs for its overall management for treatment and disposal, including the capital and operating costs for moving the excess water through the process, its cleaning, and the disposal of the treated water and any residual wastes. The treatment and disposal costs are usually more costly than the initial raw material. Often these costs (process operations and compliance costs) are not tracked by a company because the accounting process used is inadequate to perform such tracking.
Companies participating in the SGP have found significant cost savings by implementing P2 practices (USEPA 2001). Significant cost savings result in improved economic efficiency and an improved bottom line on the balance sheet, making the operation more competitive. Other advantages include the protection of employees, reduction of liabilities, and, at the same time, enhancement of the company’s business image.
Success in achieving the goals of the SGP for the metal‐finishing sector has been attributed largely to the employment of pollution prevention techniques. A principal purpose of the program was to demonstrate the attractive environmental and economic advantages offered by P2‐based approaches to waste reduction. The outcome anticipated was to “stimulate a keen awareness and appreciation” of these extremely valuable tools so that they would be adopted into everyday practice on a sector‐wide basis. In addition, the adoption of an EMS and integration into company operations ensures continued improvements (both in environmental performance and in cost savings) within the entire fabric of the participating companies.
There are many approaches to reduce pollution in various unit processes that were investigated and documented by USEPA sponsored research in the 1980s, including housekeeping and maintenance methods and management of process chemicals and rinse water. These methods are described in the EPA Capsule Report entitled Approaching Zero Discharge in Surface Finishing (USEPA 2000) and the training course document entitled P2 Concepts & Practices for Metal Plating & Finishing (AEFS, American Electroplaters and Surface Finishers Society). These learning aids address a number of process design areas such as those listed in Table 7.2.
Transitions of manufacturing operations to P2‐based systems have been demonstrated using a range of technology options from relatively simple improvements in existing process technology to more sophisticated approaches based upon significant process changes. There are numerous examples of the power of pollution prevention technologies, ranging from relatively simple improvements of water management to more sophisticated recovery processes, as documented in the results of the SGP and other programs.
MINI‐CASE STUDY (USEPA 1998): A WATER MANAGEMENT P2EXAMPLE
A California company implemented a number of relatively simple and low‐cost P2 operations: flow restrictors in rinse tanks to manage rinse water, drag‐out reduction using drip boards between process tanks and hang bars above plating tanks. Between 1997 and 2000, the plant achieved a 50% reduction in water consumption, a 25% reduction in energy consumption, and 98% metals utilization. Since October 2001, the plant has increased savings in energy and water consumption by improving reductions to 62.5 and 70% less process water from the original baseline, respectively.
For other case studies, go to access on‐line at:
- http://es.epa.gov/cooperative/topics/metcasestudies.html
- http://www.epa.gov/ORD/NRMRL/std/mtb/metal_finishing.htm#nmmsfp
Table 7.2 Pollution prevention technologies for surface finishers.
To improve in these operations | Employ these technologies and practices |
Extend bath lifereduce chemical consumptionreduce bath dumpingmaximize on‐line timemaintain product quality | improve bath chemical solution managementreduce contamination by improved housekeepingadd new continuous bath purification technologies |
Reduce water consumptionimprove water utilization to decrease water demand and sewer chargesincrease in‐plant recyclingdecrease water discharges and water intake | employ a rinse method that uses less waterreduce drag‐in and drag‐outemploy new process analysis and planning methods for water conservationuse advanced technologies for removal of chemicals to permit rinse water recycling |
Minimize wastedecrease usage of all chemicals and waterdecrease waste generationimprove recovery and recycling in‐plant | improve process management and oversightimplement an environmental management systemimprove rinsing operations as described aboveincrease in‐plant recycling of water |
Reduce the use of hazardous chemicalsreduce environmental risks and costsimprove worker safetymaintain or improve productivity and qualityacquire new or maintain existing markets where clients are “greening the supply chain” | move to less toxic chemistriesuse new finishing processes and coatingsreduce the number of stages in a line |
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