Aqua Metrology Systems

What does this live ticker show me?

This tabular ticker displays readings from the THM-100™, a fully automated online THM monitor from AMS. The THM-100 monitor is installed at the water treatment plant or in the distribution network to provide accurate and reliable data on Total THMs (TTHMs) and THM Formation Potential (THM-FP) in real-time.

The left hand column displays the date and local time (PDT) the reading was received. The right hand column identifies the concentration of TTHMs or THM-FP measured in parts per billion (ppb). If the location is marked with an *, the THM-FP level 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 permits a TTHM maximum level of 80 ppb, based on the average of four quarterly (every three months) readings at specified points in a utility’s water distribution network.

  • When TTHM/THM-FP concentration levels are well within regulatory compliance and below 60 ppb, the ticker will display TTHM/THM-FP data in green.
  • When TTHM/THM-FP concentration levels reach 60 ppb the ticker display will change to amber to alert that the water supply has the potential to exceed the regulatory compliance
  • When TTHM/THM-FP concentration levels increase to 80 ppb the ticker display will change to red to alert that the water supply has exceeded the regulatory compliance

The online THM-100 monitor enables water utilities to proactively manage their THM mitigation strategies and ensure that their water remains safe for human consumption.

What are TTHMs?

TTHMs are four organic chemicals* which form as byproducts of chlorination.
When chlorine is added to water containing 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 TTHMs.

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

Want to know more?

This data is brought to you by AMS. Our team of industry experts endeavors to develop and commercialize online, real-time metrology solutions, allowing better control over contaminants in water. If you work in the water industry and are interested in our technology contact us.  If you are a citizen and would like to understand more about TTHMs, visit


Our live ticker is designed to supplement the statutory public notice and regulatory readings provided by utilities; we accept no liability for consequential losses arising from this non-regulatory information service.