SAN ANGELO, Texas — The City of San Angelos Water Utilities Department will be temporarily changing how it disinfects the water supply from June 1-30.

What is currently used to disinfect the water is Chloramine, which is a mixture of ammonia and chlorine. In June the Water Utilities Department will be using only chlorine otherwise known as “free chlorine” which is a stronger disinfectant than chloramine. Temporarily switching to chlorine is a common practice for Municipal water systems that happens annually in order to ensure water safety in pipelines by ridding mains of residual microscopic organic particles. This process yields the highest quality of drinking water.

Citizens may see an increase in flushing fire hydrants in June. Water lines with low flow have to be flushed more often to keep chlorinated water moving through the system. Another thing you may notice is a slight change in smell, taste and appearance that will disappear after a few weeks. This may include a chlorine order and slight discoloration. The water is still safe for regular usage during this time.

The Water Utilities Department encourages kidney dialysis patients to discuss with their equipment suppliers since different equipment has varying needs and may require adjustments. The city has contacted local hospitals to alert them of the change.

There are some reverse osmosis systems that are not designed to work with water that has free chlorine. Those who own RO systems are asked to check their operations manual or system manufacturers to ensure that they will not be adversely affected by the change.

Fish tanks should need no adjustments as most are designed for removing chloramines from water and should do the same with free chlorine. Fish tank operators should confirm that with their equipment supplier. Pet stores have also been told of the conversion.

The water department will monitor chlorine levels and water-quality standards in the distribution system daily to ensure all regulatory standards are met.

The Water Utility Department Answers Frequently Asked Questions

Water system’s temporary conversion to free chlorine

The City of San Angelo Water Utilities Department will change the disinfectant used in the public water system from chloramine to free chlorine beginning June 1 for approximately four weeks.

Why is our water system making these changes to our disinfection process?

Our water system normally uses ammonia and chlorine as the main means to disinfect water. Mixing these two chemicals forms chloramine, the most common disinfectant used in the United States for water systems that use lakes and rivers as their source. Occasionally, these systems must return to free chlorine as their disinfectant for a brief time to properly maintain the distribution system. Free chlorine works better than chloramine to control thin biofilms of organics and microbes that can build up in pipelines over time. This is common preventive maintenance used by most water systems that use chloramine as their main disinfectant.

When will this start and how long will it last?

The conversion will start on June 1 and last approximately four weeks.

Will I need to do anything differently during this change?

No action is necessary. You may drink and use your water normally.

What changes to the water quality will I notice during this period?

Initially, you may notice more of a chlorine taste and smell to your water, especially in showers and sinks. Water also may also be slightly discolored in areas with low flows in water mains. These symptoms should lessen after a couple of weeks but may be present (though less noticeable) during the four-week span.

I have a fish tank. How will it affect my fish?

We recommend you check with your equipment supplier. The process you have in place to remove chloramines in the water should also remove free chlorine. No change or adjustment should be needed.

I’ve heard this can affect kidney dialysis machines. Is this true?

We recommend you check with your equipment supplier. Different equipment may have different needs or adjustments.

Will the City do anything to lessen the taste and odors we might experience during this change?

Yes, the City will implement procedures to reduce effects as much as possible. However, changes will likely occur and may persist. We will monitor free chlorine levels throughout the system each day to ensure they are at the correct levels. You may also see more flushing of fire hydrants. Water lines with low flow must be flushed more often to keep free chlorinated water moving through the system. The Water Utilities

Department does not like doing this during drought restrictions, but in some areas it will be required.

Is there a possibility of free chlorine bleaching my clothes?

Free chlorine is a stronger disinfectant than chloramine. Even though it may have more of a chlorine smell, the disinfectant residuals in the system will actually be lower than they are currently. We don’t expect problems with the bleaching of clothes. If you have brand new clothes that have never been washed, you might wash them first in cold water to let their colors “set” before using a hot water wash.

Will this process improve the quality of my water once it is completed in four weeks?

Typically, after a change to free chlorine and then back to chloramine, less disinfectant is needed to maintain residuals in the distribution system. So, if you are sensitive to the taste and smell of chloramine, you should see an improvement in water quality after the conversion.

Is there a way to reduce or remove the chlorine taste and smell during this period?

Yes. A carbon filter is effective at removing free chlorine taste and smell, as well as chloramines. If you have an existing carbon filter on your faucet, reverse-osmosis system or cartridge under the sink, these should remove any additional taste and odor during this period. These are available at local retail stores. Some are inexpensive and easy to install.

Does the taste and odor of chlorine affect everyone the same?

No. The taste and smell of chlorine in drinking water do not affect some people at all. Others with a higher sensitivity to smells could be affected. Free chlorine can give water a “swimming pool” smell.

Whom can I contact with additional questions or concerns?

Please call the Water Quality Division at 325-481-2722 for more information.