Is chlorine in my drinking water safe?

Chlorine is one of the most important tools we use to protect your health by keeping your drinking water safe from harmful microorganisms.

Not all of our service areas use chlorine. Currently chlorine is used in the following service areas:

• Homestead
• Moorehand (AWWU city water is chlorinated)
• Settlers Bay
• Sherwood
• Vallenar View

Why we use chlorine:

Disease prevention:

• Kills or inactivates harmful bacteria, viruses, and parasites
• Prevents waterborne diseases like cholera, typhoid, and dysentery
• Protects water quality as it travels through distribution pipes to your home
• Provides “residual disinfection” that continues protecting water throughout the system

EPA requirements:

• Disinfection is a Treatment Technique Rule under the Safe Drinking Water Act
• This protection has virtually eliminated waterborne disease outbreaks in the United States

Is chlorine safe?

Yes, chlorine at the levels we use is completely safe. The EPA has established Maximum Residual Disinfectant Levels (MRDLs) that protect public health while ensuring effective disinfection.

EPA safety standards for chlorine:

• Maximum level (MRDL): 4.0 mg/L (parts per million)
• Our typical levels: 0.5-2.0 mg/L
• Goal: Maintain the lowest effective level that ensures safety

We continuously monitor chlorine levels to ensure they’re high enough to protect you but low enough to minimize taste and odor while staying well below EPA limits.

Chlorine taste and odor:

You may occasionally notice a chlorine taste or smell, particularly:

• During hot summer months (when we may increase levels)
• After we flush water mains or perform system maintenance
• During certain seasonal conditions
• If water sits in your pipes for an extended period

This is normal and not a health concern. In fact, a slight chlorine smell can be reassuring that your water is properly disinfected.

Reducing chlorine taste and odor at home:

If you find chlorine taste or odor bothersome:

• Refrigerate water in a pitcher - chlorine dissipates over time and cold water tastes better
• Use a carbon filter - activated carbon effectively removes chlorine taste and odor
• Let water stand - chlorine will dissipate from an open container within a few hours
• Add lemon - a small amount can mask chlorine taste

For more detailed information, see How can I improve the taste of my drinking water?

Disinfection byproducts:

When chlorine reacts with natural organic matter in source water, small amounts of disinfection byproducts (DBPs) can form, such as:

• Trihalomethanes (THMs)
• Haloacetic acids (HAAs)

We monitor and control DBPs:

• The EPA regulates DBPs with maximum contaminant levels
• We optimize our treatment process to minimize DBP formation
• Regular testing ensures levels remain well below EPA limits
• Our annual water quality report includes DBP results

The health benefits of disinfection far outweigh the very low risks associated with DBPs at regulated levels.

Special considerations:

For most people: Chlorinated water is completely safe for all uses - drinking, cooking, bathing, and cleaning.

Kidney dialysis patients: Medical-grade water treatment systems used for dialysis already remove chlorine/chloramine. Consult with your dialysis center for specific requirements.

Fish tanks and aquariums: Chlorine is harmful to fish. Use dechlorinating products or let water sit for 24 hours before adding to tanks.

Brewing and fermentation: May affect yeast. Let water sit or use carbon filtration.

EPA approval and history:

Chlorine has been used to disinfect drinking water for over 100 years. The EPA considers chlorination one of the greatest public health achievements, credited with dramatically reducing waterborne diseases.

Alternatives to chlorine:

Other EPA-approved disinfection methods include:

• UV light (ultraviolet disinfection)
• Ozone
• Chloramine
• Chlorine dioxide

We use chlorine because it:

• Provides residual protection throughout the distribution system
• Is cost-effective and reliable
• Has a long track record of safety and effectiveness
• Meets all EPA requirements for protecting public health

Monitoring and transparency:

We test chlorine levels:

• Throughout the distribution system
• At customer taps during routine monitoring

Results are included in our annual Consumer Confidence Report, which you can access on our website or request from our office.

Bottom line:

Chlorine is essential for providing you with safe drinking water. The levels we maintain are scientifically proven to be safe while protecting you from harmful microorganisms. If you have questions about chlorine or disinfection, please contact our office.