Reference
Water system operator glossary
The terms you'll meet in rules, reports and on meter faces, in plain English.
- 4-log treatment
- Treatment that inactivates or removes 99.99% of viruses. Ground water systems that provide it do daily compliance monitoring of the disinfectant residual. More
- Apparent loss
- Water that was used but not counted: slow meters, unauthorized use, reading and data errors. More
- Chloramine
- Chlorine combined with ammonia, used by some systems as a longer-lasting disinfectant. Measured as total chlorine. More
- Chlorine residual
- The chlorine still present in water after treatment, measured in mg/L. It shows the water is still protected as it travels through pipes. More
- Combined chlorine
- Chlorine that has reacted with ammonia and other nitrogen compounds. Total chlorine minus free chlorine approximates it. More
- Community water system (CWS)
- A public water system with at least 15 connections used by year-round residents, or at least 25 year-round residents. Most mobile home parks with their own well. More
- Consumer Confidence Report (CCR)
- The annual water quality report a community water system gives its customers by July 1. More
- DLQOR
- Texas's Disinfection Level Quarterly Operating Report (Form TCEQ-20067), where ground water systems record their disinfectant residuals. More
- DPD
- N,N-diethyl-p-phenylenediamine, the reagent that turns pink in proportion to chlorine. The basis of most field chlorine tests. More
- Entry point
- Where treated water enters the distribution system, usually just after the well, chlorinator and storage. More
- Free chlorine
- Chlorine present as hypochlorous acid or hypochlorite ion, the strongest disinfecting form. What most state minimums are written in. More
- GPM
- Gallons per minute, the usual unit for pump and flow rates. More
- Ground Water Rule
- The federal rule for public water systems using ground water: sanitary survey information, source monitoring, and corrective action or 4-log treatment where required. More
- GWUDI
- Ground water under the direct influence of surface water. Treated like surface water under federal rules.
- Master meter
- A meter where water enters the distribution system or where purchased water comes in, measuring what the system delivers. More
- mg/L
- Milligrams per liter. For chlorine in water, effectively the same as parts per million (ppm).
- Monthly operating report (MOR)
- The state form summarizing a month of daily operation: residuals, water produced, chemicals used. More
- MRDL
- Maximum residual disinfectant level. For chlorine, 4.0 mg/L as a running annual average, for community and non-transient systems. More
- MRDLG
- Maximum residual disinfectant level goal, a non-enforceable health goal. 4 mg/L for chlorine.
- Non-revenue water
- Water the system produces but isn't paid for, whether used without billing or lost. More
- Non-transient non-community water system (NTNC)
- A public water system that regularly serves at least 25 of the same people over six months a year without being a community system, such as a school or factory with its own well. More
- Operator in responsible charge
- The certified operator accountable for a system's operation under the state's certification program. More
- Public water system (PWS)
- A system providing water for human consumption through pipes to at least 15 service connections, or an average of 25 people a day on 60 or more days a year. More
- Pump hour meter
- A counter of the hours a pump has run. With the source meter, it gives the pumping rate. More
- Real loss
- Water that physically leaves the system: main, service line and tank leaks, and tank overflows. More
- Register
- The rolling digits on a meter face that show the running total. Also called the totalizer or odometer. More
- Rollover
- A register passing its highest number and continuing from zero. Different from a reset, where counting starts over from a new baseline. More
- Running annual average (RAA)
- For chlorine, the average of the last 12 monthly averages, recalculated each quarter. Compliance with the MRDL is judged this way. More
- Sample siting plan
- The written plan of where and when a system collects its coliform samples, reviewed by the state. More
- Sanitary survey
- The state's on-site review of a water system's source, treatment, distribution, storage, pumps, monitoring, management and operator compliance. More
- Seasonal system
- A non-community system that starts up and shuts down each season, like many campgrounds. It must complete a state-approved start-up procedure. More
- Service connection
- A connection to the system serving a home, lot, site, building or business. States count them in their own ways. More
- Source meter
- The meter on a well's discharge, measuring the water produced. More
- Total chlorine
- Free chlorine plus combined chlorine. More
- Total coliform
- A group of bacteria used as an indicator of possible contamination. Every public water system samples for them on a schedule. More
- Transient non-community water system (TNC)
- A public water system serving people who don't stay long: campgrounds, rest areas, restaurants. More