COMBINED SEWER OVERFLOW ABATEMENT IN LOWELL, MASSACHUSETTS:BALANCING COSTS AND ENVIRONMENTAL BENEFITS

摘要

In order to develop a long-term control plan to reduce combined sewer overflows (CSOs), the city of Lowell and consultant CDM evaluated existing conditions and regulatory requirements, investigated CSO abatement technologies and methods, and considered cost and affordability. Since Lowell’s CSO discharges represented only a portion of the pollution impacting the Merrimack River water quality, the city along with other communities also initiated a comprehensive watershed-wide study. The city believes that the cost of the CSO program advocated by regulatory agencies (approximately $100 million) is not justified by its benefits, and while committed to CSO reduction, it has proposed a more cost-effective approach tied to the watershed-wide study. The current regulatory policy seems to encourage complete CSO reduction as long as sewer rates remain affordable, thus Lowell’s CSO program is a test case balancing costs and environmental impacts.