Efforts to improve water quality continue to receive attention on a state and local basis.  Many of these evaluations take a watershed approach, which means looking at all the sources of water, and therefore all potential sources of pollution, for a given body of water or geographic area.  A recently published report, WATERSHED MANAGEMENT FOR POTABLE WATER SUPPLY, ASSESSING THE NEW YORK CITY STRATEGY, states “watersheds are nature’s boundaries for surface water supplies.  Natural processes combined with human activities in watersheds determine the inherent quality of these supplies and the treatment they need for potable use.”  The drinking water for New York City is supplied by two upstate watershed systems.  In 1997 the New York City Comptroller’s Office asked the National Research Council (NRC) to provide a scientific evaluation of how to best protect these drinking water supplies.  To complete the evaluation, NRC established the Committee to Review the New York City Watershed Management Strategy, made up of 15 nationally known and widely respected experts in the areas of hydrology, watershed management, environmental engineering, ecology, microbiology, public health and epidemiology, urban planning, economics and environmental law.  In September, 2000, the Committee released the report WATERSHED MANAGEMENT FOR POTABLE WATER SUPPLY, ASSESSING THE NEW YORK CITY STRATEGY.

Highlights of the summary assessment are as follows:

  • “The watershed management program of New York City should be prioritized to place importance first on microbial pathogens, second on organic precursors of disinfection byproducts, third on phosphorus, and fourth on turbidity and sediment.”
  • “The concept of balancing watershed rules and regulations with targeted support of watershed community development is a reasonable strategy for New York and possibly other water supplies.”
  • “The committee encourages New York City and all other water supplies to be receptive to the possibility of additional treatment options.”
  • “New York City should lead in efforts to quantify the contribution of watershed management to overall reduction of risk from waterborne pollutants.”

The chapter addressing wastewater treatment, had specific conclusions and recommendations, including:

  • “Current technologies being used for OSTDS [onsite sewage treatment and disposal systems] are not adequate and do not represent Best Available Control Technology. Passive systems consisting of a septic tank and drainfield are allowed instead of requiring ATUs [aerobic treatment units], which maximize the destruction and inactivation of microorganisms.”
  • “Aerobic treatment units should be mandated for new or replacement OSTDS [onsite sewage treatment and disposal systems], and enforcement efforts should include annual inspections.”

To purchase a copy of the publication from The National Academies Press, or read it online for free, click the following link www.nap.edu/catalog/9677.html.

The USEPA has published an update of their ONSITE WASTEWATER TREATMENT SYSTEMS MANUAL.  This publication, otherwise known as the “Purple Manual,” is a widely used reference for the design and application of wastewater treatment technology.  Norweco is cited in the acknowledgements as making a significant contribution to the development of this document.  This document can be found directly on the USEPA website here www.epa.gov/onsite-wastewater-treatment-and-disposal-systems.