Have you received a public notice concerning contamination of your drinking water?

Don't panic, be alert!

Public notices are issued by your local water company when by law, the water they have supplied has not met legal requirements. If you have NOT received a notice, you may still find this website useful.


What are TTHMs?

TTHMs are four organic chemicals* which form as byproducts of chlorination. When chlorine is added to water that contains organic matter (such as algae, riverweeds or decaying leaves), residual chlorine molecules react with this harmless organic matter to form these organic chlorinated chemical compounds known as Total Trihalomethanes (TTHMs).

How are TTHMs regulated?

U.S. Environmental Protection Agency (EPA) believes that by setting maximum levels for TTHMs, water suppliers will also control the formation of other disinfection byproducts not currently regulated that may also adversely affect human health.

How are TTHMs measured traditionally?

A sample of drinking water is taken and sent for analysis at a laboratory - a process which can take up to ten days. During this time potentially millions of gallons of water will have been consumed before the water supplier knows if the contaminant levels in the sample are above the regulatory limits, which is far too late for the water supplier to warn consumers. The THM-100 is a revolutionary system that enables water suppliers to update this outdated system, ensuring greater control over the water treatment process.

Why are TTHMs regulated?

Some people who drink water-containing TTHMs in excess of the maximum contaminant level over many years may experience problems with their liver, kidneys or central nervous system and may have an increased risk of getting bladder or colorectal cancer. Studies have also shown there is a connection between exposure to TTHMs and spontaneous abortion, birth defects and growth delay.

What causes TTHM levels in water to change?

TTHM levels are affected by several factors: changes in the quality of the water that has to be disinfected (and this can be affected by drought or sudden rainfall or by changes in the source of the water); by temperature; by the quality of drinking water storage tanks and pipelines; and by the physical time it takes for the water to reach the consumer. It is very difficult for water suppliers with TTHMs in their system to predict what levels of these will be found across their system at any one point in time when there are so many variables that may have an impact.

What should I do if I receive a public notice?

Do not panic, you do not need to use alternate water supplies (e.g. bottled water). Please contact Aqua Metrology Systems, and we will contact your water supplier directly to obtain all the details you need to know. If you have health concerns you should contact your doctor. Additional information is available on the EPA's website.

*dibromochloromethane (CHClBr2), bromoform (CHBr3), chloroform (CHCl3), and dichlorobromomethane (CHCl2Br)

AMS Live Data Stream

These tabular tickers display readings from the THM-100™, a fully automated trihalomethane (THM) real-time monitoring unit from Aqua Metrology Systems. The THM-100 is installed along the water treatment network allowing the water plant operators access to THM level data as frequently as every hour. The real time data represented below is streaming simultaneously from multiple water systems across the US.

The left hand column displays the date and local time (PDT) the reading was received. The right hand column identifies the concentration of Total Trihalomethanes (TTHMs) within the water at this time measured in parts per billion (ppb). If the reading is marked with an *, the THM Formation Potential (THM-FP) level in ppb is being displayed. THM-FP is the measurement of water quality characterizing the maximum quantity of THMs that can be formed over time.

The U.S. Environmental Protection Agency (EPA) permits a maximum level of 80 ppb, based on the average of three monthly (quarterly) readings at specified points in the water supplier´s distribution system.

When the ticker is within regulation, it will display the data green. If the concentration levels reach 60 ppb this will change to amber, alerting you that your water supply has the potential of exceeding the guideline level. If the level continues to increase to 80 ppb, the ticker will alert you that your water has exceeded the maximum level and will change to red.

This revolutionary system enables water companies to continuously adjust treatment levels, ensuring drinking water remains safe for human consumption. Ultimately by ensuring greater control the THM-100 will make public notices redundant.

A recent example, the devastating Yosemite Rim Fire raised serious challenges to the Hetch Hetchy Reservoir (read full article). With real time monitoring across covered areas citizens and water technicians had the reassurance of live information to respond to immediate threats. Ultimately by ensuring greater control the THM-100 will make public notices redundant.

Water companies already using the THM-100 technology are able to act quickly to fluctuating THM levels.

"At the City of Benicia Water Treatment Plant, we strive to produce the highest quality water possible for our customers. Transparency is critical to the success of this relationship and making our THM results public illustrates not only our confidence in our ability to manage our water production to the highest levels possible, but also our confidence in the THM-100 as an instrument for monitoring THM levels." - Scott Rovanpera, superintendent of the Benicia Water Treatment Plant.

¹ Readings marked with an * are displaying TTHM and THM-FP concentrations. All other readings only display the TTHM concentration.

Free Warning Alerts

TTHMalert.com is connected directly to THM-100 monitoring equipment; enabling direct advanced notice of high TTHMs levels in areas the THM-100 is installed. Not all water companies currently commission the use of the THM-100, however as new units come online, TTHMalert.com will be automatically connected to our database.

By registering with us you will be added into our database ready to receive real-time updates. You will only receive these alerts when the TTHMs in your area are reaching and exceeding the recommended guidelines. If there is no data available in your neighborhood yet, please still register with us now. We will notify you when local monitoring commences. Our alerts will normally be issued considerably sooner than a statutory warning notice from your local water company.

Register Now

To be added into our database, please register below.

You may cancel the service at any time and no personal information or credit card details are required.

You can also follow us on Twitter @TTHMalert, or on Facebook to receive updates and related water issues regarding the regulation and safety of your water. For the security of your data please read our Privacy Policy.

About AMS

TTHMalert.com is brought to you by Aqua Metrology Systems. Founded in 2008, our team of industry experts and scientists endeavor to develop and commercialize online, real-time metrology solutions, allowing better control over contaminants in drinking water.

If you work in the water industry and are interested in our technology please refer to our commercial site: www.aquametrologysystems.com.

AMS Logo


Our service is designed to supplement the statutory public notice, we accept no liability for consequential losses due to non-delivery of an advance alert from this free service.