Ohio Surface Water Quality Criteria - Human Health (Water Supply)
Ohio water quality standards for the protection of human health at public water supply intakes. OAC 3745-1-33, Table 33-1.
Overview
These are Ohio’s water quality criteria for the protection of human health at public water supply intakes, as established in OAC 3745-1-33, Table 33-1. These criteria apply to surface waters designated for public water supply use under the Clean Water Act (CWA).
The criteria are expressed as Outside Mixing Zone Average (OMZA) concentrations - the maximum allowable average concentration in the ambient water outside the mixing zone of any discharge. They apply at the point of water supply intake.
Ohio maintains separate criteria for the Ohio River basin and the Lake Erie basin. Where a Lake Erie basin value is not listed, the Ohio River basin value applies statewide. Values marked with “a” are based on federal Maximum Contaminant Levels (MCLs) under the Safe Drinking Water Act (SDWA) rather than Ohio-derived risk-based calculations.
These standards differ from the groundwater standards used under the VAP (Voluntary Action Program). Surface water criteria protect drinking water at the intake point and account for exposure through both ingestion and dermal contact during water-related activities. For VAP groundwater standards, see our Ohio Groundwater Standards - VOCs page.
Reading This Table
Form indicates how the chemical is measured: T = total, TR = total recoverable, D = dissolved, S = soluble, free = free (un-complexed) form.
Units are micrograms per liter (ug/l) unless noted otherwise. Mf/l = million fibers per liter (asbestos only). mg/l = milligrams per liter.
“a” suffix on a value indicates it is based on an MCL or other federal standard rather than an Ohio-derived risk-based criterion.
Scientific notation (e.g., 7.710-6) indicates very low values. 7.710-6 ug/l = 0.0000077 ug/l.
Table 33-1: Human Health Criteria - Water Supply
| Chemical | Form | Units | Ohio River Basin | Lake Erie Basin |
|---|---|---|---|---|
| Acenaphthene | T | µg/l | 70 | NL |
| Acrolein | T | µg/l | 3.0 | NL |
| Acrylonitrile | T | µg/l | 0.51 | NL |
| Alachlor | T | µg/l | 2.0a | 2.0a |
| Aldrin | T | µg/l | 7.7*10-6 | NL |
| Anthracene | T | µg/l | 300 | NL |
| Antimony | TR | µg/l | 5.6 | 6.0a |
| Arsenic | TR | µg/l | 10a | 10a |
| Asbestos | T | Mf/l | 7.0a | 7.0a |
| Atrazine | T | µg/l | 3.0a | 3.0a |
| Barium | TR | µg/l | 1,000 | 2,000a |
| Benzene | T | µg/l | 5.0a | 5.0a |
| Benzidine | T | µg/l | 0.00086 | NL |
| Benzo(a)anthracene | T | µg/l | 0.012 | 0.2a |
| Benzo(a)pyrene | T | µg/l | 0.0012 | NL |
| Benzo(b)fluoranthene | T | µg/l | 0.012 | NL |
| Benzo(k)fluoranthene | T | µg/l | 0.038 | NL |
| Beryllium | TR | µg/l | 4.0a | 4.0a |
| Bromate | T | µg/l | 10a | 10a |
| Bromoform (Tribromomethane) | T | µg/l | 43 | NL |
| Butylbenzyl phthalate | T | µg/l | 0.10 | NL |
| Cadmium | TR | µg/l | 5.0a | 5.0a |
| Carbofuran | T | µg/l | 40a | 40a |
| Carbon tetrachloride | T | µg/l | 2.3 | 5.0a |
| Chloramine | T | µg/l | 4,000a | 4,000a |
| Chlordane | T | µg/l | 0.0031 | 0.00025 |
| Chlorides | T | mg/l | 250a | 250a |
| Chlorine | T | µg/l | 4,000a | 4,000a |
| Chlorine dioxide | T | µg/l | 800a | 800a |
| Chlorite | T | µg/l | 1,000a | 1,000a |
| Chloroacetic acid | T | µg/l | 60a | 60a |
| Chlorobenzene | T | µg/l | 100a | 100a |
| Chlorodibromomethane | T | µg/l | 4.0 | NL |
| Bis(2-Chloro-1-methylethyl) ether | T | µg/l | 200 | NL |
| Bis(2-Chloroethyl)ether | T | µg/l | 0.30 | NL |
| Chloroform | T | µg/l | 57 | NL |
| bis(2-Chloroisopropyl)ether | T | µg/l | 1,400 | NL |
| bis(2-Chloromethyl)ether | T | µg/l | 0.0015 | NL |
| 2-Chloronaphthalene | T | µg/l | 800 | NL |
| 2-Chlorophenol | T | µg/l | 30 | NL |
| Chromium | TR | µg/l | 100a | 100a |
| Chrysene | T | µg/l | 0.038 | NL |
| Cyanide | free | µg/l | 4.0 | 4.0 |
| 2,4-D (2,4-Dichlorophenoxy-acetic acid) | T | µg/l | 70a | 70a |
| Dalapon | T | µg/l | 200a | 200a |
| 4,4'-DDD | T | µg/l | 0.0012 | NL |
| 4,4'-DDE | T | µg/l | 0.00018 | NL |
| 4,4'-DDT | T | µg/l | 0.0003 | 0.00015 |
| Dibenzo(a,h)anthracene | T | µg/l | 0.0012 | NL |
| Dibromochloropropane | T | µg/l | 0.2a | 0.2a |
| Di-n-butyl phthalate | T | µg/l | 20 | NL |
| Dichloroacetic acid | T | µg/l | 60a | 60a |
| 1,2-Dichlorobenzene | T | µg/l | 420 | 600a |
| 1,3-Dichlorobenzene | T | µg/l | 7.0 | NL |
| 1,4-Dichlorobenzene | T | µg/l | 63 | 75a |
| 3,3'-Dichlorobenzidine | T | µg/l | 0.21 | NL |
| Dichlorobromomethane | T | µg/l | 5.5 | NL |
| 1,2-Dichloroethane | T | µg/l | 3.8 | 5.0a |
| 1,1-Dichloroethylene | T | µg/l | 0.57 | 7.0a |
| cis-1,2-Dichloroethylene | T | µg/l | 70a | 70a |
| trans-1,2-Dichloroethylene | T | µg/l | 100a | 100a |
| 2,4-Dichlorophenol | T | µg/l | 10 | NL |
| 1,2-Dichloropropane | T | µg/l | 5.0a | 5.0a |
| 1,3-Dichloropropene | T | µg/l | 2.7 | NL |
| Dieldrin | T | µg/l | 1.2*10-5 | 0.0000065 |
| Di(2-ethylhexyl)adipate | T | µg/l | 400a | 400a |
| Diethyl phthalate | T | µg/l | 600 | NL |
| 2,4-Dimethylphenol | T | µg/l | 100 | 100 |
| Dimethyl phthalate | T | µg/l | 2,000 | NL |
| 4,6-Dinitro-o-cresol (4,6-Dinitro-2-methylphenol) | T | µg/l | 2.0 | NL |
| Dinitrophenols | T | µg/l | 10 | NL |
| 2,4-Dinitrophenol | T | µg/l | 10 | 10 |
| 2,4-Dinitrotoluene | T | µg/l | 0.49 | NL |
| Dinoseb | T | µg/l | 7.0a | 7.0a |
| 1,2-Diphenylhydrazine | T | µg/l | 0.30 | NL |
| Diquat | T | µg/l | 20a | 20a |
| Dissolved solids | T | mg/l | 750/500a, | 750/500a,b |
| alpha-Endosulfan | T | µg/l | 20 | NL |
| beta-Endosulfan | T | µg/l | 20 | NL |
| Endosulfan sulfate | T | µg/l | 20 | NL |
| Endothall | T | µg/l | 100a | 100a |
| Endrin | T | µg/l | 0.03 | 2.0a |
| Endrin aldehyde | T | µg/l | 0.29 | NL |
| Ethylbenzene | T | µg/l | 68 | 700a |
| Ethylene dibromide (EDB) | T | µg/l | 0.050a | 0.050a |
| bis(2-Ethylhexyl)phthalate | T | µg/l | 3.2 | 6.0a |
| Fluoranthene | T | µg/l | 20 | NL |
| Fluorene | T | µg/l | 50 | NL |
| Fluoride | T | µg/l | 1,000 | 4,000a |
| Glyphosate | T | µg/l | 700a | 700a |
| Heptachlor | T | µg/l | 5.9*10-5 | 0.4a |
| Heptachlor epoxide | T | µg/l | 0.00032 | 0.2a |
| Hexachlorobenzene | T | µg/l | 0.00079 | 0.00045 |
| Hexachlorobutadiene | T | µg/l | 0.10 | NL |
| alpha-Hexachlorocyclohexane | T | µg/l | 0.0036 | NL |
| beta-Hexachlorocyclohexane | T | µg/l | 0.08 | NL |
| gamma-Hexachlorocyclohexane (Lindane) | T | µg/l | 0.20 | 0.20a |
| Hexachlorocyclohexane - technical grade | T | µg/l | 0.066 | NL |
| Hexachlorocyclopentadiene | T | µg/l | 4.0 | 50a |
| Hexachloroethane | T | µg/l | 1.0 | 1.0 |
| Indeno(1,2,3-c,d)pyrene | T | µg/l | 0.012 | NL |
| Iron | S | µg/l | 300a | 300a |
| Isophorone | T | µg/l | 340 | NL |
| Mercury | TR | µg/l | 0.012 | 0.0031 |
| Methoxychlor | T | µg/l | 0.02 | 40a |
| Methyl bromide | T | µg/l | 47 | NL |
| 3-Methyl-4-chlorophenol | T | µg/l | 500 | NL |
| Methylene chloride | T | µg/l | 5.0a | 5.0a |
| Nickel | TR | µg/l | 610 | NL |
| Nitrate-N + Nitrite-N | T | µg/l | 10,000a | 10,000a |
| Nitrite-N | T | µg/l | 1,000a | 1,000a |
| Nitrobenzene | T | µg/l | 10 | NL |
| Nitrosoamines | T | µg/l | 0.0080 | NL |
| N-Nitrosodibutylamine | T | µg/l | 0.063 | NL |
| N-Nitrosodiethylamine | T | µg/l | 0.0080 | NL |
| N-Nitrosodimethylamine | T | µg/l | 0.0069 | NL |
| N-Nitrosodi-n-propylamine | T | µg/l | 0.050 | NL |
| N-Nitrosodiphenylamine | T | µg/l | 33 | NL |
| N-Nitrosodipyrrolidine | T | µg/l | 0.16 | NL |
| Oxamyl (Vydate) | T | µg/l | 200a | 200a |
| Pentachlorobenzene | T | µg/l | 0.1 | NL |
| Pentachlorophenol | T | µg/l | 0.3 | 1.0a |
| Phenol | T | µg/l | 4,000 | NL |
| Picloram | T | µg/l | 500a | 500a |
| Polychlorinated biphenyls | T | µg/l | 0.00064 | 0.000026 |
| Pyrene | T | µg/l | 20 | NL |
| Selenium | TR | µg/l | 50a | 50a |
| Silvex (2,4,5-TP, | T | µg/l | 10 | 50a |
| 2-[2,4,5-Trichlorophenoxy]propionic acid | NL | NL | NL | NL |
| Simazine | T | µg/l | 4.0a | 4.0a |
| Styrene | T | µg/l | 100a | 100a |
| Sulfates | T | mg/l | 250a | 250a |
| 1,2,4,5-Tetrachlorobenzene | T | µg/l | 0.03 | NL |
| 2,3,7,8-Tetrachlorodibenzo-p-dioxin | T | µg/l | 5.0*10-8 | 5.0*10-8 |
| 1,1,2,2-Tetrachloroethane | T | µg/l | 1.7 | NL |
| Tetrachloroethylene | T | µg/l | 5.0a | 5.0a |
| Thallium | TR | µg/l | 1.7 | NL |
| Toluene | T | µg/l | 57 | 57 |
| Toxaphene | T | µg/l | 0.0028 | 0.000068 |
| Trichloroacetic acid | T | µg/l | 60a | 60a |
| 1,2,4-Trichlorobenzene | T | µg/l | 0.71 | 70a |
| 1,1,1-Trichloroethane | T | µg/l | 200a | 200a |
| 1,1,2-Trichloroethane | T | µg/l | 5.0a | 5.0a |
| Trichloroethylene | T | µg/l | 5.0a | 5.0a |
| 2,4,5-Trichlorophenol | T | µg/l | 300 | NL |
| 2,4,6-Trichlorophenol | T | µg/l | 14 | NL |
| Vinyl chloride | T | µg/l | 0.22 | 2.0a |
| Xylenes | T | µg/l | 10,000a | 10,000a |
| Zinc | T | µg/l | 7,400 | NL |
No results found.
Source: OAC 3745-1-33, Table 33-1. Most recent revision effective 4/21/2021. Full document: Ohio Water Quality Standards (PDF).
Related Resources
- Ohio Surface Water Criteria - Fish Consumption - Table 34-1 criteria for fish consumption pathway
- Ohio Surface Water Criteria - Aquatic Life - Tables 35-1 and 35-9 aquatic life protection criteria
- Ohio Water Quality Standards (full PDF) - Complete OAC Chapter 3745-1
- EPA National Recommended Water Quality Criteria - Human Health - Federal recommended criteria
Ohio water quality criteria for human health protection at public water supply intakes. Source: OAC 3745-1-33, Table 33-1. Effective 4/21/2021.