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Humboldt County, California — public water systems

At a glance

90 active public water systems are filed under Humboldt County, California in EPA's SDWIS records, together reporting 133,779 people served. The largest is City of Eureka, which reports serving 27,078 people. 45 are community water systems serving people where they live; the other 45 are non-community systems, such as schools, workplaces, campgrounds and gas stations with their own supply.

Dataset updated . Source: EPA SDWIS/ECHO, refreshed quarterly.

Active systems

90

Population served

133.8K

Community systems

45

Groundwater share

63.3%

How does Humboldt County compare with other California counties?

Humboldt County has the 29th-most active public water systems among the 201 counties listed for active California systems in EPA records; among the 72 with 3 or more systems, the median has 73. Its systems report 133,779 people served in total, the 35th-largest county figure in the state and 0.3% of the statewide total. The average system here reports serving 1,486 people, well below the California average of 5,706. Population figures are what each system reports; people served by more than one system, such as a wholesaler and the town that buys from it, are counted by each.

Where does Humboldt County's drinking water come from?

By primary water source, Humboldt County's active systems draw on groundwater (48, 53%), surface water (33, 37%), purchased groundwater (7, 7.8%) and groundwater under influence of surface water (2, 2.2%). Overall, 63% rely mainly on groundwater (including purchased groundwater) and 37% on surface water, compared with 85% and 15% across California. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, City of Eureka, draws primarily on purchased groundwater.

What kinds of water systems operate in Humboldt County?

Humboldt County's active systems break down as 45 community systems (50%), 11 non-transient non-community systems (12%) and 34 transient non-community systems (38%). A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. EPA lists their owner types as private (46%), local government (37%), state government (14%) and federal government (3.3%).

The 50 largest water systems in Humboldt County

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Active public water systems in Humboldt County, California
#Water systemCountyPopulation servedTypeSource
1Eureka, City ofHumboldt27,078CommunityPurchased groundwater
2Arcata, City ofHumboldt20,875CommunityPurchased groundwater
3Humboldt C.S.D.Humboldt19,807CommunityGroundwater
4Mckinleyville C.S.D.Humboldt16,900CommunityPurchased groundwater
5Fortuna, City ofHumboldt12,133CommunityGroundwater
6Rio Dell, City ofHumboldt3,300CommunitySurface water
7Garberville Sanitary DistrictHumboldt2,041CommunitySurface water
8Fieldbrook Glendale C.S.D.Humboldt1,845CommunityPurchased groundwater
9Del Oro Water Co-FerndaleHumboldt1,662CommunityGroundwater
10Richardson Grove Sp-State ParksHumboldt1,509Transient non-communitySurface water
11Hydesville Co. W.D.Humboldt1,366CommunityGroundwater
12Willow Creek C.S.D.Humboldt1,298CommunityGroundwater under influence of surface water
13Redway C.S.D.Humboldt1,207CommunitySurface water
14Blue Lake, City ofHumboldt1,172CommunityPurchased groundwater
15Trinidad, City ofHumboldt1,072CommunitySurface water
16Caltrans-Trinidad NbHumboldt1,000Transient non-communityGroundwater
17Sue-Meg Sp-State ParksHumboldt1,000Transient non-communitySurface water
18Gold Bluffs Beach Cg-State ParksHumboldt998Transient non-communitySurface water
19Jacoby Creek CwdHumboldt924CommunityPurchased groundwater
20Loleta C.S.D.Humboldt828CommunityGroundwater
21Resort Improvement District #1Humboldt803CommunitySurface water
22Manila Community Services Dist.Humboldt750CommunityPurchased groundwater
23Richardson Grove Campground & Rv ParkHumboldt750Transient non-communityGroundwater
24Scotia CsdHumboldt681CommunitySurface water
25Humboldt Bay MwdHumboldt680CommunityGroundwater
26Orleans C.S.D.Humboldt636CommunitySurface water
27Van Duzen - Humboldt Co. ParksHumboldt551Transient non-communityGroundwater
28Prairie Creek Sp-State ParksHumboldt500Transient non-communityGroundwater
29Miranda C.S.D.Humboldt492CommunityGroundwater
30Westhaven C.S.D.Humboldt490CommunitySurface water
31Weott C.S.D.Humboldt448CommunitySurface water
32Stone Lagoon-State ParksHumboldt402Transient non-communityGroundwater
33Orick C.S.D.Humboldt396CommunityGroundwater
34Burlington Cg-State ParksHumboldt368Transient non-communityGroundwater
35Hidden Springs Cg-State ParksHumboldt350Transient non-communityGroundwater
36Benbow-Del Oro W.C.Humboldt347CommunitySurface water
37Riverside CsdHumboldt333CommunityGroundwater
38Myers Flat M.W.S. Inc..Humboldt330CommunityGroundwater
39Palmer Creek CsdHumboldt320CommunityGroundwater
40A W Way - Humboldt Co. ParksHumboldt301Transient non-communityGroundwater
41AngelinaHumboldt300Transient non-communityGroundwater
42Big Lagoon - Humboldt Co. ParksHumboldt300Transient non-communityGroundwater
43Dean Creek ResortHumboldt283Transient non-communityGroundwater
44Cal Fire-Eel River Conservation CampHumboldt280Non-transient non-communitySurface water
45Green Diamond Resource Company - KorbelHumboldt250CommunityGroundwater
46Larrupin CafeHumboldt247Transient non-communitySurface water
47Sylvan Harbor Trailer ParkHumboldt231Transient non-communityGroundwater
48Chimney TreeHumboldt200Transient non-communitySurface water
49Founders Grove-State ParksHumboldt200Transient non-communitySurface water
50Emerald ForestHumboldt200Transient non-communityGroundwater under influence of surface water

All other water systems in Humboldt County (40)

The remaining active systems filed under Humboldt County, largest first, with the population each reports serving.

Humboldt County water systems: frequently asked questions

How many public water systems are in Humboldt County, California?

EPA's SDWIS records file 90 active public water systems under Humboldt County, California: 45 community systems (50%), 11 non-transient non-community systems (12%) and 34 transient non-community systems (38%).

Who supplies drinking water in Humboldt County, CA?

The largest community water systems filed under Humboldt County are City of Eureka (27,078 people served), City of Arcata (20,875 people served) and Humboldt C.S.D. (19,807 people served). Which system serves a particular address depends on its service area, which EPA's SDWIS records do not include; a water bill or the local utility can confirm it.

Does Humboldt County's drinking water come from groundwater or surface water?

Of the 90 active public water systems in Humboldt County, 63% draw mainly on groundwater and 37% on surface water, counting purchased supplies. The largest system, City of Eureka, uses purchased groundwater.

Where can I find a water quality report for Humboldt County?

Each community water system must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1, covering the previous calendar year. 45 community systems are filed under Humboldt County, so the report to look for is the one from the system that supplies your address.

How can I check violations for a water system in Humboldt County?

Open the system's profile from the list on this page. Each profile shows the most recent Safe Drinking Water Act violations in EPA's records, with plain-English labels and whether each one is resolved. For current compliance status, EPA ECHO is the primary source.

More California water systems

About this data

Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.

Cite as: AquaCensus, “Public water systems in Humboldt County, California”, https://aquacensus.com/water-systems/california/humboldt (data as of October 1, 2026).