California COVID-19 Cases by Sewershed with Masked Values

The California Department of Public Health aggregates confirmed COVID-19 cases by sewershed restricted locations. Confirmed cases are defined by a positive molecular test, with data available from January 1, 2021. Case counts below specific thresholds are masked according to population-based de-identification guidelines.

Use Cases

• Analyze confirmed COVID-19 case trends across different sewershed restricted locations over time.
• Study the impact of de-identification guidelines by examining masked values relative to sewershed population size.
• Assess wastewater surveillance data starting from January 1, 2021, for correlation with confirmed case reports.

Strengths

• Data is aggregated by the authoritative California Department of Public Health.
• Includes specific, documented de-identification rules for masking case counts based on sewershed population thresholds.
• Covers data from January 1, 2021, providing a defined temporal starting point for analysis.

Limitations

• Cumulative case counts are listed as 'NA' due to wastewater data starting in 2021, not 2020.
• Masking of low case numbers may obscure trends in smaller or mid-sized sewersheds.
• The dataset is archived and no longer updated as of March 17, 2025.

Provenance

Source

California Department of Public Health (CDPH)

Collection Method

Aggregation of confirmed COVID-19 cases, defined by a positive molecular test, by sewershed restricted locations.

Time Range

From January 1, 2021.

Freshness

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Geography

State of California, United States.