Unfortunately, Oklahoma ranked at the bottom of the list, receiving a score of 726. The state only fared better than Maryland and Alabama in terms of tap water quality. The study prioritized six factors - price; conservation; billing and payment; communications; and customer service.

Healthy water should generally have dissolved oxygen concentrations above 6.5-8 mg/L and between about 80-120 %.

Water that has little to no pollution (since contaminants in small amounts pose no threat to our health) is considered to be of good quality and rendered safe to drink. It can even be beneficial to our health too.

DEQ: Division of Environmental Quality. Design Flow: a facility discharge flow of process wastewater that is authorized in a National Pollutant Discharge Elimination System (NPDES) permit.

The WQI is calculated by averaging the individual index values of some or all of the parameters within five water quality parameter categories: Water clarity: turbidity (NTU*) and/or Secchi disk depth (meters or feet); Dissolved oxygen: Dissolved oxygen concentration (mg/l);

The Oklahoma Department of Environmental Quality is the lead state agency that administers the Clean Water Act Section 401 water quality certification program in Oklahoma. The purpose of these certification reviews is to determine whether a proposed discharge will comply with Oklahoma water quality standards.

DEQ also uses the standards as regulatory tools to prevent pollution of the state's waters. The Clean Water Act requires states to adopt water quality standards designating beneficial uses of the state's waters and setting criteria designed to protect those uses.