Tuolumne County public water systems

Failing or At-Risk

16systems

4,115people served (7% of total)

Not At-Risk or Not Assessed

26systems

36,996people served (64% of total)

Status classification

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

Failing9%

At-Risk21%

Potentially At-Risk21%

Not At-Risk49%

Failing

At-Risk

Potentially At-Risk

Not At-Risk

Not Assessed

Systems

5

11

26

0

Population

2,311

1,804

16,745

36,996

0

Funding since 2017

$2M

$0

$466K

$29M

$0

Key figures

53

public water systems

57,856

reported population

72%

serve 500 people or fewer

$32M

reported funding since 2017

System locations

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

Each point represents one system record.

Summary

Tuolumne County has 53 public water systems in the SAFER dataset. Of these, 16 (30%) are classified as Failing or At-Risk.

Those systems report serving 4,115 people. The county profile is also shaped by small systems: 38 systems serve 500 people or fewer.

Reported funding since 2017 totals $32M across 9 systems. Technical assistance funding totals $653K.

System counts and reported population

At-Risk systems make up 21% of listed systems and 3% of reported population. This status is concentrated in smaller systems, so it reaches fewer people than its system count suggests.

Risk profile

Risk in Tuolumne County is distributed across four dimensions. Accessibility contributes the largest share of the combined weighted risk score at 32%. Across all individual indicators, No intertie appears most often, affecting 42 of 53 assessed systems.

Water Quality

of combined weighted risk

State 33% · ▼ 1 pts

Most common flagEmerging contaminants

Accessibility

of combined weighted risk

State 36% · ▼ 3 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 14% · – 0 pts

Most common flagTotal net annual income

Water Quality

Water Quality accounts for 31% of the county’s combined weighted risk score. Emerging contaminants appears in 22 of 53 assessed systems. Water quality trends toward MCL is next, appearing in 17 of 53 assessed systems.

Each indicator was assessed for 53 systems.

Accessibility

Accessibility accounts for 32% of the county’s combined weighted risk score. No intertie appears in 42 of 53 assessed systems. Limited water sources is next, appearing in 19 of 53 assessed systems.

Indicator denominators range from 44 to 53 assessed systems.

Affordability

Affordability accounts for 22% of the county’s combined weighted risk score. Household socioeconomic burden appears in 30 of 53 assessed systems. Share of household income is next, appearing in 16 of 47 assessed systems.

Indicator denominators range from 47 to 53 assessed systems.

TMF Capacity

TMF Capacity accounts for 14% of the county’s combined weighted risk score. Total net annual income appears in 18 of 52 assessed systems. Operating ratio is next, appearing in 15 of 52 assessed systems.

Indicator denominators range from 46 to 53 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 53 systems in Tuolumne County.

Status by system size

SAFER status within each population group

Among systems serving 500 people or fewer, 15 of 38 are Failing or At-Risk. This size group has the county’s highest concentration of high-concern classifications.

Economic context

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

DAC and SDAC service areas contain 33 of 53 listed systems. Within those two groups, 10 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)1

Among 5 Failing systems, 3 report secondary 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 $32M across 9 systems. Not At-Risk systems account for 92% of that total. Reported technical assistance funding adds $653K.

Key takeaways

30%

of systems are Failing or At-Risk

That represents 16 systems reporting service to 4,115 people. That is below the statewide average of 33%.

32%

of weighted risk comes from Accessibility

The most widespread individual flag is no intertie, found in 42 of 53 assessed systems. Statewide, Accessibility accounts for 36% of weighted risk.

72%

of systems serve 500 people or fewer

Small systems account for 38 of the county’s 53 listed systems. That is above the statewide average of 63%.