Mason & Hanger Corporation - Middletown, IA
Mason & Hanger Corporation performs high explosive melt loading operations for conventional ammunition items. As a result of these operations, explosive contaminated wastewater (pink water) is generated. In order to comply with the National Pollutant Discharge Elimination System (NPDES) permit limits for effluent discharge, the pink water is routed through a series of carbon filter columns prior to discharge into an on-site creek.
This process requires close monitoring and analytical testing to assure that the permit discharge limits are not exceeded. To eliminate any chance of exceeding the discharge limits, Mason & Hanger Engineering designed a closed-loop system that utilizes the carbon treated wastewater as recycled process water.
This closed-loop system is fully operational at one site and will be implemented at two other sites in the facility within the next year.
The immediate benefit of this system is that the discharge of treated explosive contaminated wastewater has been eliminated from this one outfall, thereby precluding the possibility of a NPDES permit violation. The environmental benefit is an annual reduction of 214,000 gallons of treated wastewater being released into the environment. This figure represents 37% of the installation's total for treated wastewater. This recycling process for pink water has also contributed to M&H receiving the 1995 Environmental Quality Award from the Department of the Army and the Honorable Mention Award for the Secretary of Defense's Environmental Security Award for 1995.
The cost to convert a pink water discharge system to a closed-loop system is a major expenditure. The operating expenses are less than a discharge system and there is a savings from the reduced usage of water. In this era of ever-tightening NPDES discharge limits, the closed-loop system is worth the expenditure in both peace of mind and environmental stewardship.