PRODUCT PRE-USE ASSESSMENT AVOIDANCE OF EFFLUENT IMPACTS AT A LARGE AEROSPACE FACILITY

Resulting from massive facility upgrades undertaken to develop a state-of-the-art metal finishing facility, this large aerospace facility developed a program to assess impacts of new wet materials brought into the factory prior to use. The goal of this effort was to avoid negative effluent impacts, which could include metals and effluent toxicity permit limit violations by development and implementation of a rigorous pre-use material assessment. This program, developed by the environmental health and safety group at this facility, provides a tiered screening of proposed new material use and a mechanism to keep certain materials (e.g., cyanide, solvents) out of the facility and precluded from use.The pre-use assessment consists of:A business unit, on the factory floor, will develop a proposal to create a new wet process or modifying an existing process that would result in introduction of new materials to the wastewater treatment facility.An initial screening of the product is performed where assessment of MSD sheets and materials on hand at the facility are made. Unacceptable materials or materials which are comparable to others already in use at the factory are eliminated from use based upon this preliminary screening.For materials that “pass” this first screening level, a zero-based treatability evaluation is undertaken and effluent generated on the bench for chemical and biological analysis.This zero-based treatability analysis is performed at the proposed highest concentration influent to the waste treatment system that can include episodic events such as batch dumps and other cleanouts.Additionally, statements are obtained from the supplier of the material attesting to their understanding that no additional toxic and hazardous substances beyond those shown in the MSD sheets are to be found in the materials.If effluent toxicity is found or effluent analyses yield concentrations of materials above Clean Water Act reporting thresholds, the material is either eliminated for potential use or sent back for reassessment and loading to the business unit and the process can be repeated. The successfully achieved goal of this effort is to preclude materials from use that can have a negative effect on the wastewater effluent.The aerospace facility has successfully reduced its flow over the years by approximately 90 percent. While a state-of-the-art facility, increasing salt and surfactant levels in the effluent complicate further reductions in flow. This pre-use assessment has been highly found useful in avoiding effluent impacts. This pollution prevention step has eliminated a percentage of the materials proposed for use. Many of these are eliminated upon the first screening but certain have shown negative impacts at the bench-level. A general finding is that materials which can represent more than one percent of the wastewater flow can be found to be problematic while no negative findings have been seen below this artificial one percent threshold.A strength of this program is demonstrated by the fact that regulatory deadlines mandating this program expired several years back. The facility has opted to maintain this rigorous program as part of its normal business operations for the indefinite future. It is at this point a cost of doing business and forces floor business unit leaders to carefully assess proposed product use prior to use on the factory floor. The high level of compliance demonstrated by this facility is proof of the strength of this program.