Public Notice

In Uncategorized by Jeremy Woosley


This public notice only applies to customers being served by the Grayson County Water District Water Treatment Plant. Please click this link GCWD_PN_ Map to see if you are effected by this public notice.

Grayson Co Water District is updating its process at the Water Treatment Plant to improve your tap water quality. This change will enhance the water you receive from your tap by adding a new treatment step to the raw water drawn from Rough River.  The new process will use chlorine dioxide to oxidize the primary raw water before it undergoes conventional water treatment. This change is expected to begin on or about 11/27/2023 and is not expected to adversely affect water quality.  In fact, you may notice improvements to the odor and taste of your tap water. 

In an abundance of caution, this notice is intended to give additional detail to kidney dialysis patients, fish fanciers, breeders and/or pet shop owners who may want to take extra precautions because of the change.

Why are we changing the treatment process?

The new treatment process involves adding an alternative form of chlorine (chlorine dioxide), a more effective and efficient oxidant than liquid (free) chlorine or potassium permanganate, which were previously used for oxidation purposes at the Water Treatment Plant.  The new process will use chlorine dioxide for oxidation, taste and odor control, algae control, and removal of iron and manganese from the raw water.  Other benefits of the use of chlorine dioxide include the reduced potential for forming harmful disinfection by-products, known as Trihalomethanes (THMs). 

Is it safe to use chlorine dioxide in the water treatment process?

Chlorine dioxide is approved by the U.S. Environmental Protection Agency (EPA) for use in drinking water treatment.  In December 1998, the USEPA set levels for chlorine dioxide and its byproducts in drinking water, and the State of Kentucky also allows chlorine dioxide use that conforms to the levels specified by the USEPA.  The new chlorine dioxide injection system will be monitored daily as required by federal USEPA and Kentucky Administrative Regulations drinking water regulations.  The Grayson Co Water District will continue to ensure that your tap water meets all state and federal requirements. 

Does chlorine dioxide form any byproducts?

Chlorine dioxide disappears fairly rapidly once applied to water and is converted primarily to chlorite.  The USEPA has set levels for both chlorine dioxide and chlorite in drinking water.

What levels are safe in drinking water?

The maximum allowable levels in drinking water are 1.0 mg/L for chlorite and 0.8 mg/L for chlorine dioxide.  To ensure that levels in your tap water do not exceed these limits, the Grayson Co Water District will be limiting its chlorine dioxide dose and chlorite byproduct formation with reliable feed injection systems, on-line monitoring meters, process shut down alarms, and granular activated carbon (GAC) filtration at the Water Treatment Plant.

Why should kidney dialysis patients take extra precautions?

Though no adverse effects have been reported by dialysis clinics using potable water treated with chlorine dioxide, some health effects studies with levels significantly above the maximum allowable limit in drinking water indicate chlorite may have adverse effects on red blood cells. This change in the treatment process might pose a risk if the water is not properly treated to remove residual disinfectants (including chlorine and chloramines) prior to dialysis.

What treatment is recommended at dialysis facilities?

Dual-bed GAC, which may already be installed and used for chloramine removal at the dialysis facility, will also remove a large percentage of chlorite.  For additional reliability, SWRCB recommends that reverse osmosis (RO) be used following the GAC.

Do dialysis facilities still need to monitor for chlorine and chloramines?

Yes, it is extremely important that dialysis facilities continue to monitor for chloramines and chlorine, as tap water distributed by Grayson Co Water District will still contain these residual disinfectants after this treatment change. More importantly, the health risks of chloramines and chlorine to dialysis patients are believed to be many orders of magnitude higher than chlorite.

What precautions should be taken for fish, tanks, or aquatic life? 

Similar to chloramines and chlorine, chlorine dioxide can be deadly to certain fish.  Treatment and aging of water to be used in aquaria is more critical when water is treated with this new process.  We recommend that fish fanciers, breeders, or pet shop owners take the extra precaution of using activated carbon filters and replace the filter cartridges regularly.  

Chlorine dioxide has been used in drinking water treatment applications in the US and Europe for many years.  Even though chlorine dioxide and chlorite may be harmful to fish and may cause problems with persons on hemodialysis if the water is not adequately filtered locally, domestic water supplies properly treated with chlorine dioxide have been deemed safe to drink and safe for bathing, cooking, and all other everyday uses for potable water by federal and State authorities.

Please share this information with anyone who drinks this water, especially those who may not have received this notice directly (apartments, nursing homes, schools, and businesses).  You can do this by posting this notice in a public place or distribute copies by hand or mail. 

For more information, please contact Jeremy Woosley at (270) 259-2917 or

This notice is being sent to you by Grayson Co Water District. KY Water System ID#: KY0430616 Date distributed: 11/15/2023

Este informe contiene información muy importante sobre su agua potable. Tradúzcalo o hable con alguien que lo entienda bien.  Para más información llame a: (270) 259-2917