A $10 million wastewater pretreatment plant under construction at Hercules Inc.'s Bacchus Works should ease concerns of the Magna Water and Sewer Improvement District and pave the way for a contract agreement allowing the district to continue accepting industrial wastewater generated at the plant.

The new facility, scheduled to begin operation in November, will neutralize explosives-contaminated water created by manufacturing processes. The plant will deal specifically with nitroglycerin residues and HMX compounds. HMX is an organic explosive used in some manufacturing processes.David S. Hollingsworth, Hercules Inc. chairman and chief executive officer, said the project is just part of a $250 million environmental protection effort the company has for its worldwide holdings. The effort is expected to span the next five years. Hollingsworth said Hercules is committed to fighting pollution.

E. Richard Anderson, manager of environmental operations at the Bacchus operation, said about 25 collection facilities are also being constructed at the plant to better control wastewater flows. Some of the collection sites will be piped directly to the plant while others will require the water to be pumped into trucks and transported to the plant.

The plant will use two processes to treat the water. One, to neutralize the nitroglycerin residues, will involve heating the contaminated water to 125 degrees Fahrenheit and holding the water at that temperature for 16 hours. Anderson said this will cause the residues to break down and be neutralized through a process called caustic hydrolysis. This causes the potentially dangerous chemicals to dissolve into nitrates and organic compounds that can then be handled by the Magna treatment facility.

The second process, used to eliminate HMX, involves ultraviolet radiation. Small doses of ultraviolet light penetrate the contaminated water, causing the organic explosive material to break down into treatable compounds.

Anderson said three safeguards have been built into the system, which he said is a composite of state-of-the-art technology. He said the technology has been pilot-tested and appears to meet the needs of the Bacchus operation. The system has a number of test procedures to check treatment success before the water is released into the Magna waste system. Anderson said a recycling mechanism is also included so that water that tests unsatisfactorily can be reprocessed.

The plant is scheduled for mechanical completion on Aug. 1. Anderson said a testing period will follow, then the plant will be put into full operation. The company has until Nov. 8 to get the plant on line and to complete the collection facilities at the manufacturing sites.

In the past, the contaminated water was put into small sumps or settling ponds near the manufacturing sites. The water then either evaporated, settled into the ground (percolated), or biodegraded. From time to time, the sites were "shot" (blown up) to ensure that large buildups of explosive residues did not occur. Once the new collection systems are operating, the company will evaluate the sites for contamination and then take appropriate cleanup action so the land can be replanted.

Initially the plant will handle about 20,000 gallons daily. It is designed to handle up to 80,000 gallons per day under maximum operating conditions.