June 29, 1989: Surface Water Treatment Rule and Total Coliform Rule promulgated on this date. These are two of the most important drinking water regulations adopted by the USEPA under the Safe Drinking Water Act of 1974. A summary of the SWTR stated: “This notice, issued under the Safe Drinking Water Act, publishes maximum contaminant level goals for Giardia lamblia viruses, and Legionella; and promulgates national primary drinking water regulations for public water systems using surface water sources or ground water sources under the direct influence of surface water that include (1) criteria under which filtration (including coagulation and sedimentation, as appropriate) are required and procedures by which the States are to determine which systems must install filtration, and (2) disinfection requirements. The filtration and disinfection requirements are treatment technique requirements to protect against the potential adverse health effects of exposure to Giardia lamblia, viruses, Legionella, and heterotrophic bacteria, as well as many other pathogenic organisms that are removed by these treatment techniques. This notice also includes certain limits on turbidity as criteria for (1) determining whether a public water system is required to filter; and (2) determining whether filtration, if required, is adequate.”
Commentary: The SWTR has been changed substantially by subsequent regulations and the Total Coliform Rule has been radically altered. However, these two regulations contributed significantly to the improvement of public water supplies in the U.S. in the later part of the twentieth century.