Hardness
Moderately hard74mg/L as CaCO₃
average at both treatment plants
USGS hardness classes
About 4.3 gpg. Plant ranges span 54–96 mg/L, from soft to moderately hard.
2025
View source ↗- 1Your water
- 2Your home
- 3Your system
Your local water, explained
Concord Water Quality Report
CCWD customers in Concord: understand the report and your next step.
Contra Costa Water District’s 2025 report gives a hardness average of 74 mg/L at each treatment plant—moderately hard—and a 2.1 mg/L chloramine average. These figures apply to the utility’s reported system, not a test at a particular Concord tap.
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Your water
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These are utility measurements, not a test at your tap or a current service advisory. Sources checked October 27, 2026
Showing utility report
Contra Costa Water District (CCWD)
2025 utility report; measurement years are shown with each result
Use these results only if Contra Costa Water District (CCWD) supplies your home. County and ZIP boundaries do not confirm a water provider.
Your water at a glance
See the amount, the comparison and what it means. “Below” refers to the stated benchmark, not zero risk.
Chloramine
Below the 4 mg/L limit2.1mg/L as chlorine
system average; range ND–3.4
MRDL: 4 mg/L
Choose a filter with a verified chloramine reduction claim at the required flow.
2025
View source ↗TTHMs
Reported value below 80 ppb28µg/L (ppb)
system average; range 13–33
MCL: 80 ppb
The report’s compliance method and a home’s individual sample are different measures.
2025
View source ↗HAA5
Reported value below 60 ppb16µg/L (ppb)
system average; range 4.4–21
MCL: 60 ppb
Haloacetic acids are disinfection byproducts.
2025
View source ↗Fluoride
Below California’s 2 mg/L limit0.7mg/L
system average; range 0.6–0.9
California MCL: 2 mg/L
Fluoride reduction needs an appropriate dedicated treatment stage.
2025
View source ↗Lead
Below action level; one high sampleND90th percentile
64 sampled homes
Report action level: 15 ppb
One of 64 homes exceeded 15 ppb. The system percentile is not a guarantee for an individual tap.
June 2025
View source ↗Arsenic
Unknown, not zeroNot listedin the selected report tables
no numeric result shown
No comparison available
Ask the utility for the relevant monitoring result if arsenic is a specific concern.
2025 report
View source ↗PFAS
Non-detect does not mean zeroNot detectedutility’s drinking-water statement
no compound-level values shown here
No numeric comparison
CCWD reports no detection in its drinking water. Check its detailed PFAS results for compounds and reporting limits.
2025 report
View source ↗View Full Water ReportOpen the measured results, dates, comparisons and original utility report.
The numbers behind your report
Selected results with the original sampling dates and measurement basis. Open the utility report for every parameter, notice and footnote.
Open the complete utility report ↗
| What was measured | Reported amount | Sample year / source date | How to read it |
|---|---|---|---|
| Hardness | 74 mg/L as CaCO₃average at both treatment plants | 2025View source ↗ | Moderately hardAbout 4.3 gpg. Plant ranges span 54–96 mg/L, from soft to moderately hard. |
| Chloramine | 2.1 mg/L as chlorinesystem average; range ND–3.4 | 2025View source ↗ | Below the 4 mg/L limitChoose a filter with a verified chloramine reduction claim at the required flow. |
| TTHMs | 28 µg/L (ppb)system average; range 13–33 | 2025View source ↗ | Reported value below 80 ppbThe report’s compliance method and a home’s individual sample are different measures. |
| HAA5 | 16 µg/L (ppb)system average; range 4.4–21 | 2025View source ↗ | Reported value below 60 ppbHaloacetic acids are disinfection byproducts. |
| Fluoride | 0.7 mg/Lsystem average; range 0.6–0.9 | 2025View source ↗ | Below California’s 2 mg/L limitFluoride reduction needs an appropriate dedicated treatment stage. |
| Lead | ND 90th percentile64 sampled homes | June 2025View source ↗ | Below action level; one high sampleOne of 64 homes exceeded 15 ppb. The system percentile is not a guarantee for an individual tap. |
| Arsenic | Not listed in the selected report tablesno numeric result shown | 2025 reportView source ↗ | Unknown, not zeroAsk the utility for the relevant monitoring result if arsenic is a specific concern. |
| PFAS | Not detected utility’s drinking-water statementno compound-level values shown here | 2025 reportView source ↗ | Non-detect does not mean zeroCCWD reports no detection in its drinking water. Check its detailed PFAS results for compounds and reporting limits. |
| Hardness — Bollman plant | 74 mg/L as CaCO₃average; range 59–90 | 2025View source ↗ | Moderately hard averageBollman is the district’s Concord treatment plant. |
| Hardness — Randall-Bold plant | 74 mg/L as CaCO₃average; range 54–96 | 2025View source ↗ | Moderately hard averageThe plant’s range crosses the soft/moderately hard boundary. |
| Copper | 0.11 mg/L90th percentile | June 2025View source ↗ | Below the 1.3 mg/L action levelNone of 64 homes exceeded the action level. |
| TDS — Bollman / Randall-Bold | 212 / 199 mg/Lplant averages | 2025View source ↗ | Below the 500 mg/L secondary limitFull sample ranges were 159–281 and 137–301 mg/L. |
| Chloride — Bollman / Randall-Bold | 45 / 46 mg/Lplant averages | 2025View source ↗ | Below the 250 mg/L secondary limitThis is chloride, not the disinfectant chlorine. |
| Sulfate — Bollman / Randall-Bold | 58 / 48 mg/Lplant averages | 2025View source ↗ | Below the 250 mg/L secondary limitSulfate and sulfur odors are not interchangeable measurements. |
| Sodium — Bollman / Randall-Bold | 47 / 43 mg/Lplant averages | 2025View source ↗ | No MCL listed in this tableA softener does not remove sodium. |
In drinking water, ppm ≈ mg/L, ppb ≈ µg/L and ppt ≈ ng/L. Calculated hardness in grains per US gallon (gpg) = mg/L as CaCO₃ ÷ 17.118, rounded to one decimal. ND means below the reporting limit, not zero.
MCL is an enforceable contaminant limit; MRDL is a disinfectant limit. A PHG is a health goal, not the legal limit. Lead/copper action levels use system sampling percentiles, not a safe-tap threshold. TTHM/HAA5 comparisons use locational running annual averages.
PFAS results are compound-specific. Source monitoring, entry-point samples and tap tests are different. Notification and response levels in a utility report are not maximum contaminant levels; do not infer a compliance violation from a single value. EPA PFAS benchmarks and implementation ↗
Turn your report into a plan for your home.
Choose the system size, keep useful existing equipment, and review your filtration goals.
Source water. Sacramento–San Joaquin Delta water, with Los Vaqueros Reservoir storage and blending, treated at the Bollman and Randall-Bold plants.
Your provider needs its own report.
Continue with your home details for general filtration guidance. We will not use another utility’s numbers as your result.
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What this means for your home
Concord’s Bollman plant is one of the two treatment plants in CCWD’s report. Its hardness range is 59–90 mg/L; Randall-Bold’s is 54–96 mg/L. Confirm CCWD on the bill before using these figures. For plumbing-related concerns such as lead, a system percentile cannot substitute for sampling inside the home.
A useful local question
What filtration should a CCWD customer in Concord consider?
Start with a system whose chloramine reduction claim matches the home’s required flow. The reported hardness average is moderate, so a softener recommendation should follow measured home hardness and scale concerns. A general filter-and-softener combination is not proof of treatment for every contaminant listed in the report.
Sources and methodology
We keep each utility’s results separate, show the reported sample year, and distinguish averages, maxima and tap-sampling percentiles. Hardness classifications use USGS ranges. Missing data stays unknown.
- Contra Costa Water District (CCWD) ↗2025 utility report; measurement years are shown with each result
- Contra Costa Water District annual reports ↗
- USGS hardness classification
- EPA PFAS benchmarks and implementation
Sources checked October 27, 2026
Your water → your home → your system
Turn your report into a plan for your home.
Choose the system size, keep useful existing equipment, and review your filtration goals.
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