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Water Quality Results

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Distribution System Monitoring

Monthly samples are taken at four dedicated sampling stations located throughout the City’s water distribution system. The locations for these sites were chosen to reflect the overall water quality of the system. Samples are analyzed for boron, calcium, magnesium, hardness (as CaCO3), pH, and free chlorine.

To view the most recent distribution system water quality sampling results, click on the links below. 

Additionally, the City collects ortho-phosphate readings from the distribution system quarterly. For the most recent results, click here. After treatment at the Regional Water Treatment Facility in Woodland, the finished surface water is dosed with phosphoric acid to create ortho-phosphate for corrosion control. The target residual is 2.0 parts per million prior to entering the transmission line.

For historical distribution system water quality sampling results, click here.

Most Recent Water Hardness Test Results

August 2019

Location

parts per million

grains per gallon*

Whaleback Park (West Davis)

89

5.20

Mockingbird Place (North Davis)

87

5.09

El Macero Drive (South Davis)

59

3.45

1st Street (Central Davis)

68

3.98

 *grains per gallon is calculated by dividing the parts per million result by 17.1

 

Source Water Monitoring

To download the most recent water quality summary, click here. This summary lists the results for the 2018 Annual Sampling Event of each groundwater well and the Point of Entry for surface water (Sacramento River water).

Additional information on the City’s water quality can be found in the Annual Water Quality Reports, available online here.

 

Unregulated Contaminant Monitoring Rule

Every five years, the U.S. Environmental Protection Agency (US EPA) requires Public Water Systems to test their source water(s) for unregulated contaminants. The City completed sampling requirements for Unregulated Contaminant Monitoring Rule 4 (UCMR4) in 2018. This rule required sampling at selected wells, sampling stations, and the Point of Entry for surface water for three Assessment Monitoring (AM) lists of constituents.

The monitoring events are grouped by a number and include tests for different constituents. AM1 included sampling at selected wells and the Point of Entry for inorganic chemicals, pesticides, alcohols, and organic chemicals. AM2 included sampling the distribution system for haloacetic acids. AM3 included sampling at the Point of Entry for cyanotoxins. The following is the list of constituents which were sampled for during UCMR4: 

Constituents Sampled for in UCMR4

AM1

AM2

AM3

Germanium

Bromochloroacetic Acid (BCAA)

Total Microcystin

Manganese

Bromodichloroacetic Acid (BDCAA)

Anatoxin-a

Alpha-Hexachlorocyclohexane

Chlorodibromoacetic Acid (CDBAA)

Cylindrospermopsin

Chloropyrifos

Dibromoacetic Acid (DBAA)


Dimethipin

Dichloroacetic Acid (DCAA)


Ethoprop

Monobromoacetic Acid (MBAA)


Oxyfluorfen

Monochloroacetic Acid (MCAA)


Profenophos

Tribromoacetic Acid (TBAA)


Tebuconazole

Trichloroacetic Acid (TCAA)


Total Permethrin (cis & trans)



Tribufos (DEF)



Butylated hydroxyanisole (BHA)



o-Toluidine



Quinoline



2-Methoxyethanol



Ally alcohol



n-Butyl alcohol


 

  

The table below lists the unregulated constituents that were detected during UCMR4 sampling events. The US EPA uses the data from UCMR sampling events to develop potential regulation on these constituents. 

UCMR4 Results

Constituent

Unit

Year Sampled

Range

Manganese*

ppb

2018

<10 – 200

Bromochloroacetic Acid (BCAA)

ppb

2018

0.67 – 3.6

Bromodichloroacetic Acid (BDCAA)

ppb

2018

0.59 – 2.6

Chlorodibromoacetic Acid (CDBAA)

ppb

2018

0.37 – 1.3

Dibromoacetic Acid (DBAA)

ppb

2018

0.43 – 1.7

Dichloroacetic Acid (DCAA)

ppb

2018

0.96 – 5.6

Trichloroacetic Acid (TCAA)

ppb

2018

0.72 – 3.8

*Although manganese is regulated under the California Code of Regulations, UCMR4 required testing of this constituent at a lower detection level.