As a precautionary response to COVID-19, Ohio EPA is currently operating with most staff working remotely. If you are working with our staff on a current project and you know the name of the employee you are working with, email them at firstname.lastname@epa.ohio.gov or call them directly. The Agency website has contact information for every district, division, and office. In order to reach us, please contact Ohio EPA’s main phone line at (614) 644-3020 or the main line for the division or office you are trying to reach.

After March 23, our district offices and Central Office will be temporarily closed and will have increasingly limited ability to receive deliveries, plans, etc. All entities are encouraged to submit plans, permit applications, etc., electronically where there are existing avenues to do so, such as the eBusiness Center (eBiz). Please refer to the list of available services on the main eBiz webpage. We encourage you to make use of all that apply, even if you have not used eBiz in the past. Plans under 25 MB can be emailed. For large plans over 25 MB, entities should work with the reviewer/division to upload via LiquidFiles. Directions for submitting docs via LiquidFiles is available on YouTube. We apologize for the inconvenience and thank you in advance for your understanding. If you wish to send hard copies of documents to any of Ohio EPA’s district offices, the best method to ensure we receive these documents is to send them via U.S. Mail. Since all offices are closed, deliveries outside of U.S. Mail (FedEx, UPS) will likely be returned because the offices are closed and deliveries cannot be made.

To report a spill or environmental emergency, contact the spill hotline (800) 282-9378 or (614) 224-0946

OAC Chapter 3745-1 Water Quality Standards 

The following is a complete list of the rules in Chapter 3745-1 of the Ohio Administrative Code.  A description of the contents of this chapter is available here. This description includes a link to tables summarizing the aquatic life and human health numerical water quality criteria and values contained in and developed pursuant to this chapter.


As of February 6, 2017, the OAC Chapter 3745-1 Water Quality Standards have been reorganized. The division has created two tables to help make this transition as smooth as possible:

List of variances pursuant to paragraph (L) of OAC 3745-1-38 and paragraph (D)(12) of OAC 3745-33-07.

The Water Body Use Designation Index  is an alphabetical listing of the water bodies in rules 3745-1-08 to 3745-1-32 with their associated rule and page numbers.

Map of Ohio drainage basins and associated rule numbers.

  • 3745-1-08 Hocking river drainage basin 

  • 3745-1-09 Scioto river drainage basin 

  • 3745-1-10 Grand river drainage basin  

  • 3745-1-11 Maumee river drainage basin 

  • 3745-1-12 Sandusky river drainage basin 

  • 3745-1-13 Central Ohio tributaries drainage basin

  • 3745-1-14 Ashtabula river drainage basin

  • 3745-1-15 Little Beaver creek drainage basin

  • 3745-1-16 Southeast Ohio tributaries drainage basin

  • 3745-1-17 Southwest Ohio tributaries drainage basin 

  • 3745-1-18 Little Miami river drainage basin

  • 3745-1-19 Huron river drainage basin 

  • 3745-1-20 Rocky river drainage basin 

  • 3745-1-21 Great Miami river drainage basin 

  • 3745-1-22 Chagrin river drainage basin 

  • 3745-1-23 Portage river drainage basin 

  • 3745-1-24 Muskingum river drainage basin  

  • 3745-1-25 Mahoning river drainage basin 

  • 3745-1-26 Cuyahoga river drainage basin 

  • 3745-1-27 Black river drainage basin

  • 3745-1-28 Vermilion river drainage basin 

  • 3745-1-29 Wabash river drainage basin

  • 3745-1-30 Mill creek drainage basin 

  • 3745-1-31 Lake Erie standards 

  • 3745-1-32 Ohio river standards 

  • 3745-1-33 Water quality criteria for water supply use designations

  • 3745-1-34 Water quality criteria for the protection of human health [fish consumption]

  • 3745-1-35 Aquatic life and wildlife criteria  

  • 3745-1-37 Water quality criteria for recreation use designations and aesthetic conditions 

  • 3745-1-38 Variances from water quality standards for point sources 

  • 3745-1-39 Site-specific modifications to criteria and values

  • 3745-1-40 Methodologies for development of aquatic life criteria and values

  • 3745-1-41 Methodology for deriving bioaccumulation factors

  • 3745-1-42 Methodologies for development of human health criteria and values for the lake Erie drainage basin

  • 3745-1-43 Methodology for the development of wildlife criteria for the lake Erie drainage basin

  • 3745-1-44 Whole effluent toxicity provisions

  • 3745-1-50 Wetland definitions 

  • 3745-1-51 Wetland narrative criteria 

  • 3745-1-52 Numeric chemical criteria for wastewater discharges to wetlands 

  • 3745-1-53 Wetland use designation 

  • 3745-1-54 Wetland antidegradation