Napa County public water systems

Status classification

Share of listed systems, followed by the count, reported population, and funding in each status.

Failing13%

At-Risk23%

Not At-Risk58%

Failing

At-Risk

Potentially At-Risk

Not At-Risk

Not Assessed

Systems

4

7

1

18

1

Population

5,600

23,390

200

98,793

1,000

Funding since 2017

$0

$2M

$0

Key figures

31

public water systems

128,983

reported population

68%

serve 500 people or fewer

$2M

reported funding since 2017

System locations

Points show reported system locations. They do not represent service-area boundaries.

Each point represents one system record. Nearby or overlapping points can conceal multiple systems.

Summary

Napa County has 31 public water systems in the SAFER dataset. Of these, 11 (35%) are classified as Failing or At-Risk.

Those systems report serving 28,990 people. The county profile is also shaped by small systems: 21 systems serve 500 people or fewer.

1 system is listed as Not Assessed, serving 1,000 people, so Not Assessed should not be read as a low-risk classification.

Reported funding since 2017 totals $2M across 1 system. Technical assistance funding totals $747K.

System counts and reported population

Not At-Risk systems make up 58% of listed systems and 77% of reported population. A few large systems drive that population, so it reaches more people than its system count suggests.

Risk profile

Risk in Napa County is distributed across four dimensions. Accessibility contributes the largest share of the combined weighted risk score at 35%. Across all individual indicators, No intertie appears most often, affecting 23 of 30 assessed systems.

Water Quality

of combined weighted risk

State 32% · ▼ 7 pts

Most common flagWater quality trends toward MCL

Accessibility

of combined weighted risk

State 36% · ▼ 1 pts

Most common flagNo intertie

Affordability

of combined weighted risk

State 17% · ▲ 5 pts

Most common flagHousehold socioeconomic burden

TMF Capacity

of combined weighted risk

State 15% · ▲ 4 pts

Most common flagTotal net annual income

Water Quality

Water Quality accounts for 25% of the county’s combined weighted risk score. Water quality trends toward MCL appears in 13 of 30 assessed systems. Past presence on Failing list is next, appearing in 7 of 30 assessed systems.

Each indicator was assessed for 30 systems.

Accessibility

Accessibility accounts for 35% of the county’s combined weighted risk score. No intertie appears in 23 of 30 assessed systems. Limited water sources is next, appearing in 13 of 30 assessed systems.

Indicator denominators range from 28 to 30 assessed systems.

Affordability

Affordability accounts for 22% of the county’s combined weighted risk score. Household socioeconomic burden appears in 11 of 30 assessed systems. Extreme water bill is next, appearing in 6 of 25 assessed systems.

Indicator denominators range from 25 to 30 assessed systems.

TMF Capacity

TMF Capacity accounts for 18% of the county’s combined weighted risk score. Total net annual income appears in 15 of 29 assessed systems. Operating ratio is next, appearing in 11 of 29 assessed systems.

Indicator denominators range from 23 to 30 assessed systems.

Patterns and context

The countywide totals hide important differences among systems. The panels below show how SAFER status varies by system size and service-area economic status, what conditions appear among Failing systems, and how reported funding is distributed across the 31 systems in Napa County.

Status by system size

SAFER status within each population group

Among systems serving 500 people or fewer, 8 of 21 are Failing or At-Risk. The highest concentration occurs among systems serving 3,301 to 10,000, at 50%.

Economic context

Orange shows Failing or At-Risk systems within each service-area group

DAC and SDAC service areas contain 9 of 31 listed systems. Within those two groups, 6 systems are Failing or At-Risk.

Conditions among Failing systems

A system can appear under more than one condition

Frequently listed primary analytes

Total Haloacetic Acids (Haa5)2

Among 4 Failing systems, 2 report primary MCL violation. The most frequently listed primary analytes are Total Haloacetic Acids (Haa5).

Reported funding

Totals since 2017 and number of systems reporting funding

Funding since 2017 totals $2M across 1 system. At-Risk systems account for 100% of that total. Reported technical assistance funding adds $747K.

Key takeaways

35%

of systems are Failing or At-Risk

That represents 11 systems reporting service to 28,990 people. That is above the statewide average of 33%.

35%

of weighted risk comes from Accessibility

The most widespread individual flag is no intertie, found in 23 of 30 assessed systems. Statewide, Accessibility accounts for 36% of weighted risk.

68%

of systems serve 500 people or fewer

Small systems account for 21 of the county’s 31 listed systems. That is above the statewide average of 61%.