Ozaukee County, Wisconsin — public water systems
At a glance
249 active public water systems are filed under Ozaukee County, Wisconsin in EPA's SDWIS records, together reporting 92,392 people served. The largest is Port Washington Waterworks, which reports serving 12,853 people. 48 are community water systems serving people where they live; the other 201 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
249
Population served
92.4K
Community systems
48
Groundwater share
99.2%
How does Ozaukee County compare with other Wisconsin counties?
Ozaukee County has the 8th-most active public water systems among the 90 counties listed for active Wisconsin systems in EPA records; among the 74 with 3 or more systems, the median has 140. Its systems report 92,392 people served in total, the 16th-largest county figure in the state and 1.8% of the statewide total. The average system here reports serving 371 people, about 21% below the Wisconsin average of 469. 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 Ozaukee County's drinking water come from?
By primary water source, Ozaukee County's active systems draw on groundwater (247, 99%), surface water (1, 0.4%) and purchased surface water (1, 0.4%). Overall, 99% rely mainly on groundwater (including purchased groundwater) and 0.8% on surface water, compared with 99% and 0.6% across Wisconsin. Groundwater means the system draws its water from wells or springs fed by underground aquifers. The county's largest system, Port Washington Waterworks, draws primarily on surface water.
What kinds of water systems operate in Ozaukee County?
Ozaukee County's active systems break down as 48 community systems (19%), 47 non-transient non-community systems (19%) and 154 transient non-community systems (62%). 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 (88%), local government (9.6%) and state government (2.8%).
The 50 largest water systems in Ozaukee County
🔒 Create a free account to export CSV| # | Water system | County | Population served | Type | Source |
|---|---|---|---|---|---|
| 1 | Port Washington Waterworks | Ozaukee | 12,853 | Community | Surface water |
| 2 | Cedarburg L & W Commission | Ozaukee | 12,500 | Community | Groundwater |
| 3 | Grafton Waterworks | Ozaukee | 12,269 | Community | Groundwater |
| 4 | Mequon Water Utility | Ozaukee | 11,152 | Community | Purchased surface water |
| 5 | Saukville Waterworks | Ozaukee | 4,268 | Community | Groundwater |
| 6 | Belgium Waterworks | Ozaukee | 2,493 | Community | Groundwater |
| 7 | Fredonia Waterworks | Ozaukee | 2,279 | Community | Groundwater |
| 8 | Homestead High School | Ozaukee | 1,650 | Non-transient non-community | Groundwater |
| 9 | Mcdonalds Mequon | Ozaukee | 1,524 | Transient non-community | Groundwater |
| 10 | Concordia University | Ozaukee | 1,500 | Community | Groundwater |
| 11 | Walgreens in Mequon | Ozaukee | 912 | Transient non-community | Groundwater |
| 12 | Kwik Trip | Ozaukee | 817 | Transient non-community | Groundwater |
| 13 | Mequon Trail Townhomes | Ozaukee | 615 | Community | Groundwater |
| 14 | Christ Church Mequon | Ozaukee | 600 | Transient non-community | Groundwater |
| 15 | Huntington Park | Ozaukee | 600 | Community | Groundwater |
| 16 | Christ Alone Lutheran School & Church | Ozaukee | 559 | Non-transient non-community | Groundwater |
| 17 | Waynes Drive-in | Ozaukee | 510 | Transient non-community | Groundwater |
| 18 | St Francis Borgia Catholic Church | Ozaukee | 510 | Transient non-community | Groundwater |
| 19 | Missing Links Golf Range | Ozaukee | 502 | Transient non-community | Groundwater |
| 20 | Alliance Bible Church | Ozaukee | 457 | Transient non-community | Groundwater |
| 21 | Village Bp | Ozaukee | 452 | Transient non-community | Groundwater |
| 22 | River Barn Park | Ozaukee | 450 | Transient non-community | Groundwater |
| 23 | St Francis Borgia Educational & Activity Center | Ozaukee | 420 | Non-transient non-community | Groundwater |
| 24 | Welcome Mart | Ozaukee | 405 | Transient non-community | Groundwater |
| 25 | Ozaukee Congreg Church & Parish House | Ozaukee | 402 | Transient non-community | Groundwater |
| 26 | Ozaukee Congreg Fellowship Hall | Ozaukee | 401 | Transient non-community | Groundwater |
| 27 | Wi Dnr Harrington Beach Shower Bldg | Ozaukee | 400 | Transient non-community | Groundwater |
| 28 | Glen Oaks Office Park | Ozaukee | 400 | Non-transient non-community | Groundwater |
| 29 | Camp Jcc Gym | Ozaukee | 368 | Transient non-community | Groundwater |
| 30 | Hb Performance Systems Inc. | Ozaukee | 315 | Non-transient non-community | Groundwater |
| 31 | Portview Church | Ozaukee | 308 | Transient non-community | Groundwater |
| 32 | J Mobil Mequon | Ozaukee | 304 | Transient non-community | Groundwater |
| 33 | Camp Jcc East End Well | Ozaukee | 300 | Transient non-community | Groundwater |
| 34 | Kingdom Hall Jehovahs Witnesses - Mequon | Ozaukee | 300 | Transient non-community | Groundwater |
| 35 | Beechwood Farms Estates | Ozaukee | 300 | Community | Groundwater |
| 36 | Bog Golf Course the Barn | Ozaukee | 300 | Transient non-community | Groundwater |
| 37 | Westchester Lakes Subdivision | Ozaukee | 300 | Community | Groundwater |
| 38 | Cedar Valley Cheese | Ozaukee | 265 | Non-transient non-community | Groundwater |
| 39 | Park Place Subdivision | Ozaukee | 260 | Community | Groundwater |
| 40 | Camp Jcc Pool & Lodge | Ozaukee | 258 | Transient non-community | Groundwater |
| 41 | Cornerstone Church | Ozaukee | 253 | Transient non-community | Groundwater |
| 42 | Trinity Ev Lutheran School & Church - Freistadt | Ozaukee | 250 | Non-transient non-community | Groundwater |
| 43 | Reuter Pavilion | Ozaukee | 250 | Transient non-community | Groundwater |
| 44 | Riversite | Ozaukee | 250 | Non-transient non-community | Groundwater |
| 45 | Christian Life Church | Ozaukee | 229 | Transient non-community | Groundwater |
| 46 | The Highland House | Ozaukee | 205 | Transient non-community | Groundwater |
| 47 | Chucks Place | Ozaukee | 204 | Transient non-community | Groundwater |
| 48 | Virmond Park | Ozaukee | 200 | Transient non-community | Groundwater |
| 49 | Covered Bridge Park | Ozaukee | 200 | Transient non-community | Groundwater |
| 50 | Brighton Ridge Subdivision | Ozaukee | 200 | Community | Groundwater |
All other water systems in Ozaukee County (199)
The remaining active systems filed under Ozaukee County, largest first, with the population each reports serving.
- Pines Subdivision200
- Center for Jewish Life200
- River Centre East Well199
- Haddonstone Subdivision195
- Hahn Ace190
- Camp Jcc Bayit183
- Mequon Umc & North Shore Preschool174
- Bog Golf Course Clubhouse170
- Bays Nail Spa170
- Vineyard Community Church162
- Country Terrace Condo Homes160
- Dr Dawg156
- Sugar Maple Nature School155
- Unitarian Church North155
- Milas Bakery155
- Mee Kwon Park Clubhouse154
- New Frontiers Preschool152
- Holy Cross Catholic Church150
- Osprey Mobile Home Park150
- Wi Dnr Harrington Beach Campground Handpump150
- Kohls Floor Covering138
- Circle B Recreation Center & Bar137
- Yellow Rock Real Estate135
- River Centre West Well135
- Vintage Estates130
- Century Estates 1130
- Village Heights130
- East Towne Square 1340130
- Homestead Hs Pavilion125
- Walgreens in Thiensville122
- Kenilworth Subd120
- Ataco Steel Shop120
- North Shore Soccer United120
- Us Bank Mequon115
- Mequon on the Square Condominium Owners Association Inc.110
- Bmo Bank109
- Prime Minister Family Restaurant107
- Pliers Full Circle105
- Old Fashioned Supper Club104
- Homeplate Asylum103
- The Five Pillars Supper Club103
- Edgewater Golf Club102
- Hamilton Haus Tavern102
- Mequon Office Complex 11516 Bldg100
- Bella Via Dance Studio100
- Jorgensen Conveyors Inc.100
- Norscot Group Inc.100
- Bog Golf Course Halfway House100
- Wyngate Subdivision100
- River Lake Subdivision100
- Bog Golf Course West Comfort Station Tee 3100
- Ravine Farms Hm Owners Assoc100
- Grace Lutheran100
- Woodridge Estates100
- Bog Golf Course East Comfort Station Tee 14100
- Mequon Office Complex 11514 Bldg100
- Bel Mar Offices I & Ii99
- Ozaukee Daycare Center - Ulao 298
- St Johns Lutheran Church98
- Emr LLC Dba 5 Corners Truck & Auto97
- New World Montessori School96
- Donges Bay 540195
- Christ Alone South Campus92
- Thiensville Professional Park90
- Linden Lane Apts 11790
- St Vincent De Paul Country Thrift Store89
- Lakeside Development East & West Bldgs88
- Highland Colony Estates Condo88
- Five Corners Retail87
- Crossroads Presbyterian Church & Preschool86
- Rays Mequon LLC85
- River Trails Estates Water Users84
- Grand Ave Apartments80
- Daystar Properties80
- Laurel Lakes 60880
- Village Center South78
- Super Sky Products Inc.78
- Glaze77
- Little Red School House75
- Alberta Subdivision75
- Wi Dnr Harrington Beach Welcome Center & North Picnic75
- Wi Dnr Harrington Beach Visitor Center75
- Lions Den Gorge Co Park75
- Range Line Inn75
- Wi Dnr Harrington Beach Quarry Lake75
- Linden Lane Apts 14175
- Mequon Colony Estates75
- Mequon Retail Ii LLC75
- Ozaukee Skateland74
- North Shore Preschool & Child Care72
- Gordie Boucher Ford of Thiensville Inc.70
- Granite Microsystems70
- Williamsburg 207 209 and 21470
- Dp Properties65
- Genmet Corp65
- Skygen USA64
- Toast63
- Smilee Dental60
- Faith Baptist Church Port Washington60
- Mequon Parc Apartments LLC60
- Riveredge Nature Center58
- Hawthorne Hills Co Pk Club Hse57
- New Day Inc.56
- East Field Office Center56
- White Rabbit55
- Galleria Offices55
- Hawthorne Hills Co Pk Maintenance Shop55
- Carpets Galore54
- Village Center - South Middle52
- Korner Q LLC52
- Merchants Square52
- Heydens Garden Center52
- Central Bark Doggy Day Care52
- Eglehoff Lawn50
- Laurel Lakes 50850
- The Hub50
- Fire Ridge Golf Club50
- Wi Dnr Harrington Beach S Pic50
- Memories50
- Wi Dnr Harrington Beach Pucketts Pond Area50
- Thiensville Mequon Small Animal Clinic50
- Stonecroft Condominium Assn50
- Schwais Meats and Sausage50
- Ghost Town Tavern & Restaurant50
- Waters Edge Condominium Association50
- Johnson School Bus Service Inc. Port Wash49
- Spankys Hideaway48
- Jt Petroleum48
- Wulffs Island Sybaris Motel48
- Concord 1 Fund LLC48
- Williamsburg 20648
- Cedar Creek Motorsports48
- Tres Jolie Solace47
- Mequon Marketplace Wells Fargo46
- River Oaks of Mequon46
- Wayside Nursery45
- Cedar Crest Specialties45
- East Towne Offices Jv44
- Five Corners Professional Bldg43
- Schmidt & Bartelt Funeral Home42
- Cedar Creek Bridal Inc.41
- Heidel Rd Apts 15240
- Heidel Rd Apts 13940
- Bog Golf Course Greens Keeper Building40
- Do It Best Hardware40
- Riteway Bus Service-Cedarburg40
- Colour Bowl Salon & Wellness the40
- Five Corners Dodge39
- Waubeka Fire Dept & Waubeka Fire Hall37
- Seek Inc.37
- Thiensville Mill Professional Bldg37
- Shipyard Bar the37
- Snider Mold Co35
- Ozaukee Co Hwy Dept Cedarburg35
- Cedarburg Town Hall34
- Towne Square 123 LLC33
- Williamsburg 22032
- North Shore Dental32
- Clark Oil Stn 364 N Pt Washington Rd32
- Dds-Sc32
- Ozaukee Family Services32
- Cde Properties31
- Tfb Enterprize Property LLC30
- Fire Factory the30
- Pw Lake View Estates LLC30
- Nowhere30
- Chase Bank-Mequon30
- Fromm Family Foods LLC30
- Village Glen Apts30
- Between the Greens30
- Mequon Nature Preserve29
- Baymont Inn & Suites29
- Lux Dental28
- St Boniface Episcopal Church28
- Caseys on Wauwatosa Road27
- East Towne Veterinary Clinic27
- Riverview Inn27
- Mequon Water Trust26
- Tendick Park25
- The Landmark - Mequon25
- Waubedonia County Park25
- H H Peters Youth Camp25
- Mee Kwon Park Barn25
- Stony Hill Pub & Grill25
- Prohealth Chiropractic Center25
- River Outpost25
- Open Door Bible Church25
- Kingdom Hall of Jehovahs Witnesses Pt Wash25
- Saukville Gun Club25
- Pleasant Valley Park25
- Schramka Densow Funeral Home25
- River Edge Nature Center - Sugarbush House25
- Dawg House25
- River Garden Apts25
- North Shore Country Club Restroom25
- Badger Campsite25
- Ozaukee Co Fish & Game25
- Mequon Rotary Park25
- Pioneer Village Train Station Well25
Ozaukee County water systems: frequently asked questions
How many public water systems are in Ozaukee County, Wisconsin?
EPA's SDWIS records file 249 active public water systems under Ozaukee County, Wisconsin: 48 community systems (19%), 47 non-transient non-community systems (19%) and 154 transient non-community systems (62%).
Who supplies drinking water in Ozaukee County, WI?
The largest community water systems filed under Ozaukee County are Port Washington Waterworks (12,853 people served), Cedarburg L & W Commission (12,500 people served) and Grafton Waterworks (12,269 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 Ozaukee County's drinking water come from groundwater or surface water?
Of the 249 active public water systems in Ozaukee County, 99% draw mainly on groundwater and 0.8% on surface water, counting purchased supplies. The largest system, Port Washington Waterworks, uses surface water.
Where can I find a water quality report for Ozaukee 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. 48 community systems are filed under Ozaukee 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 Ozaukee 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 Wisconsin water systems
- All Wisconsin public water systems· 11,056 active
- Oneida County· 345 systems
- Dane County· 300 systems
- Washington County· 268 systems
- Walworth County· 252 systems
- Kenosha County· 227 systems
- Chippewa County· 218 systems
- How to find out who supplies your drinking water
- How to find and read your annual water quality report
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 Ozaukee County, Wisconsin”, https://aquacensus.com/water-systems/wisconsin/ozaukee (data as of October 1, 2026).