Confidential Plastics Manufacturer: A Case Study for Zinc
Based upon a survey of SMARTS, many facilities have transitioned from baseline status to level 1 within the first year of the new industrial general permit. Facilities that monitor for zinc have exceeded the numeric action level (NAL) and must develop programs to reduce zinc concentrations in stormwater discharge. Through their innovative approach, The Company. has almost achieved NAL for zinc concentrations without the use of costly treatment options.
The purpose of this paper is to present a case study regarding the reduction of zinc concentrations in stormwater discharge. This study demonstrates that through implementation of strategic housekeeping practices, process improvement, customized training and incentive programs, zinc concentrations at a plastics manufacturing facility can be reduced from 2.5 mg/l to 0.3 mg/l within a single sampling year.
We will present the methodology for process improvement and the effective incentive program developed to create a culture of team work and ownership of the stormwater program.
The final step to return to baseline will be the use of roof drain downspout filters to further remove zinc from stormwater discharge.
The Company’s Torrance, California facility manufactures and assembles durable molded plastic cases, flashlights, and remote area lighting [Standard Industrial Classification (SIC) Code: 3089 (Plastics Products, not elsewhere classified)]. The molded products are produced using injection molding, in which plastic pellets are heated to a pliable forming temperature, compressed, and injected into a specific shape in a mold, then trimmed to create a usable product.
BMP Corrective Actions Recommendation
Zinc is a common constituent commonly present in both motor oil and hydraulic fluid. During periods of little or no precipitation, traces of motor oil and hydraulic fluid can build up on paved surfaces. This build-up can also occur in the dust and sediment that absorbs these fluids. Parking areas, loading docks, and equipment storage areas may be sources of leaked fluid contributing to an increase in zinc in stormwater discharge. In many cases the source of zinc in the stormwater discharge is from a galvanized metal roof and downspout system. (Fact sheet: Oregon DEQ – Reducing Zinc in Industrial Stormwater).
Zinc is used in the manufacture of tires. Tires contain zinc at about 1% by weight. Tire tread wear releases particles of zinc laden dust. Common sources of tire dust are forklifts, trucks, and truck trailers. When they make tight turns, a considerable amount of zinc is released.
Often the way to control zinc at its source begins with good housekeeping practices. These include covering materials and working areas, providing containment for fluid storage, and adopting cleanup measures. Using a lean process improvement protocol, the Company systematically mitigated zinc sources. In addition to implementing the lean program, an incentive driven program has been incorporated into the individual goals for pollution prevention team members. The incentive program identifies individuals in the act of doing the right thing and rewards them for it. Incentives range from restaurant gift cards for extraordinary performance of the team lunches.
The incentive program has enhanced the housekeeping program at the facility through additional diligence on each person’s role to maintain the facility and reduce potential stormwater exposure to zinc.
In addition to the incentive program, employees received site specific customized training from a QISP.
As a result, the 2016-2017 zinc NAL has dropped to approximately 0.3 mg/L from 2.5 mg/L. The facility will enter Level 2 at the end of the 2016-2017 reporting year. Since The Company has implemented only source control measures, the next step is treatment with roof drain downspout filters. The facility expects to achieve final compliance and after the stormw
Ms. Hubbard has provided expert consultation for 25 years. She is a Trainer of Record for the Construction General Permit and for the Industrial General Permit. Ms. Hubbard has demonstrated her expertise and experience in storm water by identifying relevant provisions and identifying methods for ensuring compliance with each permit. She develops and revises key facility compliance documents including: Storm Water Pollution Prevention Plans (“SWPPPs”); Monitoring and Reporting Plans (“MRPs”); sampling protocols; and facility Best Management Practices (“BMPs”).