06/18/2022
City of Las Vegas process to treat and deliver water to your tap.
1) Divert Gallinas river water off the river.
2) Water is piped to the settling basin to settle out the turbidity in the water such as organics
3)Water is directed to City raw water storage through miles of transmission line.
4) Bradner, Peterson and Storrie are used to store up to 1300 acre feet (423 MG) where the water has more time to settling out and to be available to treat as needed.
5) Water is then piped to the clarifiers where dosing of aluminum sulfate and polymer occurs for coagulation, flocculation and sedimentation.
Coagulation is the destabilization of colloidal particles brought about by the addition of a chemical reagent called as coagulant. Flocculation is the agglomeration of destabilized particles into microfloc and after into bulky floccules which can be settled called floc.
6) Debris settles, also called sludge, and is eventually sent it to the sludge lagoon for disposal.
7) Water is then sent through one of our four filters using slow sand filtration (anthricite) to remove more of the turbidity.
8) Filters are backwashed and the valves actuators are maintained to ensure continuous operation.
9) Sodium hypochlorite is produced on site. Chlorine gas cylinders have not been used for over a decade.
10) Water is then sent to the clearwells give the water contact time with the sodium hypochlorite for disinfection.
11) Following the contact time the water is pumped to the 5 Million Gallon tank, aka Cabin site, for distribution to the community through hundreds of miles of distribution lines that are maintained by the distribution division and service lines that belong to the customer.
12) Water is at your tap.
PLCs aka Programmable Logic Controllers are used to assist with the automated operation of the system. These are maintained by technicians qualified to work on the TESCO PLC.
Operators test system water daily for turbidity and chlorine residual to ensure the water is safe to drink and meets or exceeds the EPAs safe drinking water standards
Some of wtp staffs Daily & weekly tasks include but are not limited to:
accessing the canyon to collect USGS flow data,
assessing water quality,
adjusting the diversion,
adjusting the 18 in valve in compliance with OSE rotation schedule,
taking measurements to verify volume in Peterson & Bradner reservoirs & Storrie lake,
calculating the correct dosing for alum and poly,
backwashing filters,
makeomh valving changes for transferring raw water,
jar testing,
collecting measurements from piezomenters,
sample collections,
collecting data for temperature,
collecting clorine residuals,
pump, mixer and valve maintenance.
Staff submit daily, weekly, monthly, quarterly and annual reporting including monthly data, capacities, netdmr, water diversion, water consumption, awwa annual lost water, annual gallons per capita per day consumption and annual EPA required water quality/consumer confidence annual reports
Operators are certified through the State of New Mexico Environment Department Drinking Water Bureau Operator Certification program
There are four levels of water operators with certain tasks such as process changes only allowed with a level 4 present.
The Las Vegas system requires a level 4 to operate.
Currently the city and our contracted staff have two level 4's, two level 2s, one level 1 and three uncertified.
