Is Oshkosh, WI tap water safe?
The short answer
Neither of the 2 utilities serving Oshkosh has a result above a legal limit or action level, or a health-based violation since 2016, in EPA’s and Wisconsin’s records.
Oshkosh Waterworks, which serves the most people here, has 3 results above the health goal. The worst: Lead at 6.1 ppb, above the health goal. Health goals are stricter than legal limits and are not enforced.
The water from Oshkosh Waterworks is hard, typically 170 mg/L (9.9 grains per gallon). How Wisconsin’s water compares.
A town can be served by more than one utility, and some homes are on private wells. The name on your water bill tells you which is yours, and your ZIP code narrows it down. They are listed by how many people each serves in Oshkosh’s ZIP codes, from EPA’s estimates.
- Open report
Oshkosh Waterworks
Wisconsin · serves 63,000 people · about 28,200 in Oshkosh
3 results above the health goal. The worst: Lead at 6.1 ppb, above the health goal. Hardness: hard, typically 170 mg/L (9.9 grains per gallon).
No health-based violations since 2016
- Open report
Algoma TN Sanitary Dist 1
Wisconsin · serves 3,935 people · about 610 in Oshkosh
2 results above the health goal. The worst: Arsenic at 0.19 ppb, above the health goal. Hardness: very hard, typically 310 mg/L (18.1 grains per gallon).
No health-based violations since 2016
What handles it
Each of these is certified, on a certifier’s listing, for a result above a line in Oshkosh Waterworks’s water, which serves the most people here. Another utility’s report names what handles its own results.
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Aquasana SmartFlow Reverse Osmosis (AQ-SFRO2)
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Lead, Arsenic
Brondell Capella RC250 Reverse Osmosis System
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Lead, Arsenic
Water testing near Oshkosh
The 3 labs Wisconsin certifies closest to Oshkosh, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
UW-Oshkosh Env. Research & Innovation Ctr
Oshkosh, WI · about 3 miles
Certified for bacteria, nitrate, metals
University of Wisconsin - Oshkosh
Sturgeon Bay, WI · about 3 miles
Certified for bacteria
University of Wisconsin - Oshkosh
Manitowoc, WI · about 3 miles
Certified for bacteria
Wisconsin State Laboratory of Hygiene: Well water test kits ordered by phone and shipped free; you pay to mail the sample back, and the lab bills you after testing. Tests run from bacteria alone to a homeowner package covering bacteria, nitrate, fluoride, metals, hardness, volatile organic compounds and atrazine. Bacteria is $35, nitrate $35, lead $38, and the homeowner package $450, as of July 1, 2026. Public Environmental and Water Testing Prices, Wisconsin State Laboratory of Hygiene.
All 156 certified labs for WisconsinWhich ZIP codes are in Oshkosh: Census 2020 relationship files. Which utilities serve them, and how many people: EPA SDWIS and EPA’s service area map. Each utility’s results: EPA UCMR 5, EPA SDWIS, and EPA’s and the state’s compliance monitoring, as its report lists them. How they are measured: methodology. Certified labs: Wisconsin DNR and DATCP, certified and approved drinking water laboratories; distances from the Census 2020 ZIP code tabulation area gazetteer.
Near Oshkosh
Towns nearby with a page of their own.
What to do next
- Read Oshkosh Waterworks’s full reportEvery result with its dates, the violations, and the certification claim that handles each finding.Open the report
- Filters for LeadRanked by certification and what they cost over five years.The best water filters for lead, ranked
- On a private well?No utility tests a well. A certified lab test is the first step.How to test well water