Recycled Water Quality Data

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Recycled water used in Dublin and San Ramon meets all regulatory requirements for unrestricted reuse as well as guidelines for managing salts in the groundwater basin under the Tri-Valley.

The DSRSD laboratory tests the parameters listed in the table on a monthly basis to ensure recycled water used for irrigation will not harm landscaping, as well as to monitor salts returned to the watershed.

Recycled Water Quality Data, Calendar Year 2015

Constituent Unit Average Range
Alkalinity (as CaCO3) mg/L 299 260 - 370
pH standard unit 7.32 6.87 - 7.69
Conductivity µmhos/cm 1550 1320 - 1760
Total Dissolved Solids mg/L 724 599 - 820
Calcium mg/L 49 36 - 80
Magnesium mg/L 29 15 - 46
Potassium mg/L 18.5 17.1 - 23.4
Sodium mg/L 179 162 - 199
Sulfate mg/L 87.3 71.1 - 106
Boron mg/L 0.559 0.479 - 0.721
Ammonia mg/L  31.2 23.9 - 38.8
Nitrite (as N) mg/L 2.2 0.63 - 3.4
Nitrate (as N) mg/L .23 < 0.08 - 0.47
Chloride mg/L 240 197 - 293
Total Hardness (as CaCO3) mg/L 243 200 - 348
Calcium Hardness (as CaCO3)
mg/L
122
90 - 200
Selenium
µg/L
< 1.0
< 1.0 - < 1.0
Arsenic
µg/L
1.1
< 1.0 - < 1.4
Chromium
µg/L
< 1.2
< 1.0 - 2.8
Silica (Total) mg/L  16.0 11.4 - 19.7
Total Coliform Bacteria MPN  < 2* < 2 - 30
Manganese µg/L 40.3 33.6 - 48.8
Total Kjeldahl Nitrogen mg/L  33 25 - 40
*Median
Abbreviations: mg/L = milligrams per liter; µmhos = micromhos per centimeter; µg/L = micrograms per liter; MPN = most probable number
 
Most plants thrive with recycled water's higher nutrient content but some plants are sensitive to the higher salt content. www.TriValleyWaterWise.com has a list of plants known to tolerate higher salt content, as does East Bay Municipal Utility District's award-winning book, Plants and Landscapes for Summer-Dry Climates of the San Francisco Bay Region.