Tapcensus

Water quality for ZIP code 93401

ZIP 93401 covers San Luis Obispo, Los Ranchos, and Edna in San Luis Obispo County, California, one of 23 ZIP codes in the county. 172 active public water systems serve the county; 54 had an EPA violation in the past three years.

Most likely your provider

Golden State Water Company Edna CA4010023 · Community water system · Ground water
Serves 1,495 people Rules violated, past 3 years 0 Last sanitary survey Aug 28, 2025 Distance 1.1 mi

Your location is within the outer bounds of this system's EPA service area.

View system details EPA facility report

Other community water systems in San Luis Obispo County

71 systems, nearest first
SystemServesStatusRules violated, 3 yrDistance
Lopez Project
 69 1 1.3 mi
Afuera de Chorro Water Company
 85 1 1.9 mi
Edna Valley Ranch East
 132 0 3.4 mi
Higuera Apartments
 30 3 3.5 mi
San Luis Obispo Water Department
 49,534 0 3.7 mi
Baron Canyon Mutual Water Co.
 81 0 4.2 mi
Anza Vineyard Estates Mutual Water CO
 60 0 4.5 mi
H2o, INC
 70 1 4.9 mi
Nacimiento Water Project
 0 0 5.4 mi
Varian Ranch Mutual Water
 105 0 5.5 mi
Irish Hills Mutual Water CO
 135 0 5.8 mi
Avila Valley Mutual Water CO
 75 0 6.0 mi
Bassi Ranch Mutual Water Co.
 85 2 6.1 mi
Bear Valley Water Company
 45 2 6.1 mi
Pismo Beach Water Department
 7,944 2 6.3 mi
Monte Sereno Mutual Benefit Water
 65 0 6.4 mi
San Miguelito Mwc
 1,600 1 6.7 mi
Terra de Oro Water Company
 38 0 7.4 mi
Avila Beach Community Services District
 1,630 0 7.5 mi
Las Ventanas Ranch
 108 0 7.5 mi
Canyon Crest Mutual Benefit WC
 133 0 7.6 mi
Country Hills Estates
 60 0 7.6 mi
California Mens Colony
 15,000 0 7.7 mi
City of Arroyo Grande Utilities Division
 17,963 1 7.9 mi
City of Grover Beach Public Works Dept
 12,701 0 8.0 mi
All 72 community water systems in San Luis Obispo County
Non-community systems in San Luis Obispo County (100: schools, campgrounds, workplaces, restaurants)

These systems serve places you visit rather than homes.

SystemServesStatusRules violated, 3 yrUnresolved
Strasbaugh, INC
 200 1 0
Noll Properties
 100 0 0
Edna Valley Vineyards
 30 0 0
Fiero Lane Water Company, Inc.
 324 0 0
Slo Partners
 40 1 1
Parsons Water Supply
 35 0 0
J M Sims Water Supply
 34 0 0
Waste Connections Water CO
 35 1 0
Horizon Lane Water Supply
 32 0 0
Holdgrafer & Associates
 30 0 0
Tmc Suburban, LLC
 25 0 0
Tank Farm Business Park
 45 2 1
141 Suburban Road Water Supply
 25 1 0
Vachell Water System
 150 1 1
Paragon Triangle Water Supply
 50 0 0
Center of Effort Winery
 75 0 0
Octagon Barn Center Association
 200 0 0
Elks Lodge #322
 40 3 1
Tiger Water Supply
 1,600 0 0
Toyota San Luis Obispo
 57 0 0
Chamisal Vineyards
Cayucos 		40 0 0
Madonna Inn Water Company
 120 3 1
Congregation Beth David
 25 0 0
Playa Dulce
 35 0 0
Sycamore Mineral Springs Resort
 200 1 1
Coastal Christian School
 650 0 0
Biddle Regional County Park
 27 0 0
Talley Farms Labor Housing
 90 0 0
Branch Elementary School
 253 0 0
Santa Margarita KOA
 70 0 0
Port San Luis Harbor District
 125 0 0
Lopez Recreation Area
 100 0 0
Santa Margarita Recreation Area
 150 0 0
Pacific Dunes Ranch
 26 0 0
Laetitia Vineyard & Winery INC
 62 0 0
Santa Margarita Ranch Headquarters
Cayucos 		62 0 0
Greenheart Farms
 91 0 0
Ball Tagawa Growers
 60 0 0
Precision Mutual Water Company
 25 1 0
Zoo Med-Winterhaven
Cayucos 		80 1 0
Speedling, INC
 40 0 0
Sheridan Road Mutual Water Association
 38 1 1
Cerro Alto Campground
 30 1 0
Montana de Oro State Park
 990 1 0
Granite Ridge
 50 0 0
Jack Ready Imagination Park
Cayucos 		200 0 0
Halfway Station
 25 1 0
Cuyama Lane Water Company
 25 3 1
Loading Chute
 25 1 0
Creston Elementary School
 100 0 0
All non-community systems
About this data

Water systems are matched to San Luis Obispo County, the county this ZIP code lies in, nearest to the ZIP code's centre first. Your exact provider depends on your address and connection; the largest community water system in a county is usually the city or town utility. Distances are measured to the centre of the service area EPA publishes for the system or, for systems without one, to the centre of the first town EPA lists the system as serving, from Census Bureau place files.

ZIP code areas and town boundaries come from the U.S. Census Bureau's 2020 ZCTA files.

Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The California records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.