4.0 Introduction

The most cost-effective approach for controlling biosolids quality is to limit the types and amounts of pollutants discharged into the local sewer system or treatment plant headworks. Publicly owned treatment works (POTWs) are responsible for limiting, where necessary, the character and volume of pollutants being discharged into their sewage-collection systems. In addition to improving the opportunities for biosolids and wastewater recycling, other reasons for limiting the discharge of certain pollutants include protection of the treatment facility, receiving water quality, and worker health and safety. POTWs should control the discharge of pollutants to their sewage-collection systems through the development and implementation of technically based local wastewater discharge limits [26].

4.1 The Clean Water Act

In 1948, the U.S. Congress enacted the original Federal Water Pollution Control Act, which authorized the U.S. Surgeon General of the Public Health Service to work with federal, state, and local agencies in preparing comprehensive pollution control plans for interstate rivers [16,20]. The 1948 legislation also authorized a financial assistance program specifically designed to aid local governments desiring to improve their sewage works programs [16]. Although approved by Congress, no federal funds were appropriated for this purpose.

Since its passage, the 1948 Federal Water Pollution Control Act has been amended many times. Two of the most important sets of amendments occurred in 1972 and in 1977 [16,20]. The 1972 amendments (PL 92-500) not only increased the level of federal funding appropriated for the improvement of local wastewater treatment facilities and sewage collection systems but also...