The Kentucky Division of Water (DOW) prohibits discharges from wastewater treatment plants (WWTPs) within 5 miles upstream from any public water supply intake. DOW also prohibits a public water supply from being located within 5 miles downstream of a WWTP discharge. These two analogous, yet independent, prohibitions were previously known as the Five Mile Policy.

Effective September 7, 2017, an amendment to 401 KAR 8 (Public Water Supply) officially incorporated the language of the Five Mile Policy into 401 KAR 8:100 Section 1(d), the regulation that identifies procedures for design, construction, and approval of public water supply facilities. (Because the language of the policy has been incorporated as regulation, the policy itself no longer exists.) Included with incorporation of the policy was an update to the language. The most significant change is variance procedures for siting of new or expanded public drinking water intakes. Previous variance procedures focused on requirements necessary to demonstrate that a new or expanded WWTP discharge would not significantly impact a downstream drinking water intake. The amended language also requires new or expanded drinking water intakes located within 5 miles of an upstream WWTP discharge to demonstrate that finished water will be in compliance with drinking water standards established in 401 KAR Chapter 8.

One additional change is that the policy now applies only to WWTP discharges, and not all wastewater discharges. Even with this change, the number of facilities potentially impacted by the 5-mile prohibition is still significant. According to DOW records, Kentucky has more than 325 permitted WWTPs and 309 public water systems that withdraw or purchase surface water. The regulation will limit where new or expanded WWTPs and drinking water intakes can be located. Moving forward, we can expect that future proposed amendments to 401 KAR Chapter 5 (Water Quality) will make the policy part of regulation in that chapter as well.

William Shane is an Environmental Engineer at Smith Management Group. William can be reached at