Finished Water Monitoring at the San Juan-Chama Drinking Water Project Surface Water Treatment Plant
After treatment, finished water is stored in two 10 million gallon below ground storage tanks. (one pictured in foreground).
USEPA sets regulations that limit the amount of certain substances in drinking water. USEPA defines where and how often samples for each substance must be collected and how they must be analyzed. The table below shows only the substances found in compliance monitoring for the finished water at the Surface Water Treatment Plant. For surface water, USEPA also requires that specific treatment techniques are used and that the treatment techniques are effective.
2015 Results of Finished Water Compliance Monitoring at the San Juan-Chama Drinking Water Project Surface Water Treatment Plant
||Maximum Contaminant Level (MCL)
||Maximum Contaminant Level Goal (MCLG)
A measure of cloudiness of the water. It is a good indicator of the effectiveness of the filtration.
|1 Nephelometric Turbidity Unit (NTU)
|95% of the finished water samples must be less than 0.3 NTU
||100% of samples taken in each month were less than 0.3 NTU.|
|Total Organic Carbon (TOC)
||TT (annual average is <2.0 PPM)
||ND (<1.0 PPM)
||ND (<1.0 PPM)
||Naturally present in the environment.|
||Human and animal fecal waste.|
||Erosion of natural deposits. |
||Erosion of natural deposits. |
||Maximum Residual Disinfectant Level (MRDL)
||Maximum Residual Disinfectant Level Goal (MRDLG)
||Disinfectant (sodium hypochlorite)|
|PPM = Parts Per Million PPB = Parts Per Billion|
Treatment Technique (TT): A required process intended to reduce the level of a contaminant in drinking water.
The Purification Process
Safe Drinking Water Act standards are designed to provide maximum protection for the public’s health. Surface water is treated according to these health based standards at the San Juan-Chama Surface Water treatment plant. Here’s how:
- Water withdrawn from the Rio Grande is treated with a coagulant, ferric chloride, to remove particles. The particles bind together, becoming heavy and sink to the bottom. Polymer helps by making small particles clump together.
- The water is then exposed to ozone gas to kill potentially harmful microscopic organisms. Ozone is also used to breakdown naturally occurring organic material.
- Next, a multistage filtration system is used to remove any remaining microscopic particles from the water. *Granular activated carbon (GAC) removes taste and odor compounds found in surface water.
- As water completes the treatment process, chlorine is added to disinfect and protect it on the way to your tap. The water is also treated to control the corrosion of pipelines and home plumbing.
The Water Authority uses advanced computer technologies to move water through the distribution system and monitor water quality. The entire treatment process is designed to provide drinking water that meets or exceeds all state and federal Safe Drinking Water Act standards for water quality.
Regulated Substances we test for and have not detected in Surface Water Treatment Plant Finished Water
(USEPA Method Detection Limit in parentheses)
|Antimony (<1 PPB)
Beryllium (<1 PPB)
Cadmium ( <1 PPB)
|Chromium (<1 PPB)
Cyanide (<5 PPB)
Mercury (<0.2 PPB)
|Selenium (<5 PPB)|
Thallium (<1 PPB)
|Alachlor (<0.2 PPB)
Atrazine (<0.1 PPB)
Benzene (<0.5 PPB)
Benzo(a)pyrene [PAH] (<0.02 PPB)
Carbofuran (<0.9 PPB)
Carbon Tetrachloride (<0.5 PPB)
Chlordane (<0.2 PPB)
Chlorobenzene (<0.5 PPB)
2,4-Dichlorophenoxyacetic acid (2,4-D) (<0.1 PPB)
Dalapon (<1.0 PPB)
1,2-Dibromoethane (EDB) (<0.01 PPB)
1,2-Dibromo 3-chloropropane (DBCP) (<0.02 PPB)
Di(2-ethylhexyl) adipate (<0.6 PPB)
Di(2-ethylhexyl) phthalate (<0.6 PPB)
Dichloromethane (<0.5 PPB)
o-Dichlorobenzene (<0.5 PPB)
p-Dichlorobenzene (<0.5 PPB)
1,2-Dichloropropane (<0.5 PPB)
|cis-1,2- Dichloroethylene (<0.5 PPB)
trans-1,2- Dichloroethylene (<0.5 PPB)
1,1-Dichloroethylene (<0.5 PPB)
1,2-Dichloroethane (<0.5 PPB)
Dinoseb (<0.2 PPB)
Dioxin (2,3,7,8-TCDD) (waived)
Diquat (<0.4 PPB)
Endothall (<9 PPB)
Endrin (<0.01 PPB)
Ethylbenzene (<0.5 PPB)
Glyphosate (<6 PPB)
Heptachlor (<0.04 PPB)
Heptachlor epoxide (<0.02 PPB)
Hexachlorobenzene (<0.1 PPB)
Hexachlorocyclopentadiene (<0.1 PPB)
Lindane (<0.02 PPB)
Methoxychlor (<0.1 PPB)
|Oxamyl (Vydate) (<2.0 PPB)|
Pentachlorophenol (PCP) (<0.04 PPB)
Picloram (<0.1 PPB)
Polychlorinated biphenyls (PCBs) (<0.1 PPB)
Simazine (<0.07 PPB)
Styrene (<0.5 PPB)
Tetrachloroethylene (<0.5 PPB)
Toluene (<0.5 PPB)
Toxaphene (<1.0 PPB)
2,4,5-TP (Silvex) (<0.2 PPB)
1,2,4-Trichlorobenzene (<0.5 PPB)
1,1,1-Trichloroethane (<0.5 PPB)
1,1,2-Trichloroethane (<0.5 PPB)
Trichloroethylene (<0.5 PPB)
Vinyl Chloride (<0.5 PPB)
Xylenes (Total) (<0.5 PPB)
|E. coli (Presence/Absence)
||Total Coliform (Presence/Absence)
|Gross Alpha Particle Activity (<3 pCi/L)
Radium 228 (<1 pCi/L)
|Gross Beta Particle Activity (<4 pCi/L)
Uranium (<1 PPB)
|Radium 226 (<1 pCi/L)|
Source Water Monitoring
for the San Juan-Chama Drinking Water Project
Just How Safe Is It?
For many years, the Water Authority has monitored the Rio Grande to establish a water quality baseline. Samples are collected at various sites along the river from the Heron Lake outlet to Albuquerque’s diversion dam site. Heron Lake stores San Juan-Chama water. Visit USGS website for monitoring results.
It takes about three hours for water to travel from the diversion dam (pictured on left) to the settled water ponds at the surface water treatment plant. After settling for at least a day in the ponds, it only takes two or three hours of treatment to produce the clean, finished drinking water pictured on the right.
The monitoring results compare favorably to USEPA drinking water quality standards. Because no metals, minerals, or nutrients nor organic substances have been detected in excess of USEPA standards, river water will meet requirements for those substances. Likewise, levels of radionuclides detected in the river water are far below USEPA standards and the risk of radioactivity potentially flowing from Los Alamos is extremely low.
Water treatment will remove particulate matter from the water including turbidity, sediment and microbial contaminants such as bacteria, Giardia and Cryptosporidium. The Water Authority monitored for Cryptosporidium in the San Juan-Chama surface water (source water) from June 2008 to May 2010. Cryptosporidium was detected at low levels in only four out of the 24 monthly samples collected. No additional treatment is required because of the low occurrence of Cryptosporidium in the San Juan-Chama surface water. A second round of monitoring for Cryptosporidium began in 2015 and will continue through the spring of 2017. No Cryptosporidium oocysts were detected in any samples collected during 2015.
Ozone and granular activated carbon filtration are effective in removing organics, including pharmaceutically active compounds that may have found their way into the river. If such compounds show up, they will be oxidized, then absorbed onto the filters.
Surface water treatment plant operator checks the settling rate.
Additional samples will be collected every year to determine water quality changes over time. This information will assist the Water Authority in modifying or refining treatment or identifying the need for additional treatment to ensure the high quality of our drinking water.
Download Results for Voluntary Monitoring
From 2007-2008, the Water Authority operated a Pilot Plant. Results of source and finished water monitoring from that effort are provided below:
2007 Pilot Plant: Source Water Quality Voluntary Monitoring Results
2007 Pilot Plant: Finished Water Quality Voluntary Monitoring Results
2008 Pilot Plant: Source Water Quality Voluntary Monitoring Results
2008 Pilot Plant: Finished Water Quality Voluntary Monitoring Results
Since the San Juan-Chama Drinking Water Project came online, the Water Authority has conducted additional monitoring. Results from late 2008 through 2011 are summarized below:
San Juan Chama Drinking Water Project Source Water Quality Voluntary Monitoring Results 2008-2011
San Juan Chama Drinking Water Project Finished Water Quality Voluntary Monitoring Results 2008-2011
Pharmaceuticals & Personal Care Product Occurrence Monitoring Report
Pharmaceuticals & Personal Care Product Occurrence Monitoring Report Update - March 2012