Final 2010 Integrated Water Quality Monitoring and Assessment Report
The draft 2012 Integrated Report is available. For more information, go here.
The Ohio Environmental Protection Agency (Ohio EPA) Division of Surface Water (DSW) has completed the
Ohio 2010 Integrated Water Quality Monitoring and Assessment Report. The report indicates the general condition of Ohio's waters and identifies waters that are not meeting water quality goals. Prepared in accordance with
federal guidance, the report satisfies the Clean Water Act requirements for both
Section 305(b) water quality reports and Section 303(d) lists of impaired waters.
Minor revisions to the report were made based on public comments. The final report, including responses to public comments (Section D6), is available below.
Section 303(d) TMDL Priority List for 2010
The Total Maximum Daily Load (TMDL) priority list for 2010, as required by Section 303(d) of the Federal Water Pollution Control Act, 33 U.S.C. Section 1313(d), is contained in the Integrated Report in Section L4. The list indicates the waters of Ohio that are currently impaired and may require TMDL development in order to meet water quality standards. The waters are ranked according to level of impairment to help indicate which have the greatest need for TMDL development.
The report describes the procedure that Ohio EPA used to develop the list and indicates which areas have been selected for TMDL development during FFY 2011 through 2012.
U.S. EPA approved Ohio's 2010 Section 303(d) list on June 2, 2010.
How can I download a copy of the report?
The report is available below in Adobe Acrobat format.
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What's the best way to use the report?
Your approach would depend on your primary interest — a particular area or watershed, a statewide perspective on water quality, or perhaps an interest in TMDL activity.
Section K contains a collection of maps that provide an overview of water quality on a statewide basis.
Those with an interest in Ohio's response to the Clean Water Act requirements or the TMDL program should start with the report text in Sections B through J.
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What does the report say about my watershed?
To locate information on a particular watershed or large river, use the new assessment summary pages. These pages may be searched by clicking on progressively smaller watersheds, or by stream name. You can also electronically search the tables in Section L [PDF 1,752K] (use the "Find" function in Adobe) using the stream name or watershed code.
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What's new in the 2010 report?
While the overall approach to the report is the same as the past few reporting cycles, Ohio EPA has made significant changes to the report.
Listing by Beneficial Use
The most profound change to the 2010 Integrated Report is the change from listing by assessment unit to listing by each of the four beneficial uses within an assessment unit. In past reports, an impairment of one beneficial use caused the assessment unit to be listed as impaired regardless of the status of other uses. In the 2010 report, Ohio is listing by beneficial use within each assessment unit, so uses that are attaining water quality standards and those with no data to assess are being removed from the list of impaired waters (i.e., “delisted”). In general, listing by use allows more information to be transmitted and presents a more accurate picture of water quality in Ohio.
Size of Assessment Units
Ohio continues to use a watershed-based listing approach, but is shifting to a smaller watershed assessment unit size. Some of the large river units are also being split into smaller pieces. Reporting at a finer scale allows a more refined picture of water quality in Ohio – just as a photograph with more “pixels” results in a clearer picture. To accommodate this change, methodologies for each of the listed uses – aquatic life, recreation, human health (via fish tissue), public drinking water supply – were revised.
Recreation Use Methodology
Several significant changes have been made to the recreation use methodology. First, the methodology is changing from a pooled to a site-by-site analysis, similar to that used for the aquatic life use. The indicator organism is shifting from fecal coliform to E. coli, which aligns with Ohio’s new water quality standards for recreation use.
Human Health Methodology
The methodology for the human health use (using fish tissue contaminant samples) was changed to be consistent with the methodology described in U.S. EPA’s 2009 guidance for implementing the methylmercury water quality criterion.
Report Format
Having more assessment units necessitates a change in how the report is presented. Past reports included about 100 pages of text, about 100 pages of summary tables, and detailed summary sheets for each of the 357 assessment units (watershed, large river and Lake Erie). For the 2010 report, the detailed summaries of assessment units alone would number more than 1,600 pages. The report will continue to be available both in paper and electronic formats. The detailed assessment unit information will be available only online.
New Content
For the first time in many years, the report includes a section on ground water quality in Ohio. The report also previews a possible methodology for including lakes in the aquatic life use listing decisions in 2012 (if rules are adopted). Looking further into the future, the report includes more discussion of wetlands, including possible pathways to including wetlands in future listing decisions.
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Are there more or fewer impaired waters?
While the water quality results do not show a major difference in water quality from 2008, there were a significant number of delistings from the 303(d) list. Delistings were due primarily to the change from listing by a single overall category for each assessment unit to listing by each beneficial use in each of the new, smaller assessment units.
For the administrative delisting process, the 2008 overall result was distributed to each of the beneficial uses, then the 2010 use results were used to “correct” the 2008 listing. This conservative process was developed to ensure that listings approved by U.S. EPA in the 2008 303(d) list were not delisted without good cause and that the process is as transparent as possible.
Most delistings were due to the change from reporting using a single overall category to reporting by each use, either use alone or combined with new methodology and/or new data. Completion of TMDLs was also a significant factor. A total of 3,238 watershed assessment unit/uses were delisted, and 125 were added to the 303(d) list. A total of 75 large river assessment unit/uses were delisted; two were added (due to new data). Four assessment unit/uses were delisted for the Lake Erie nearshore units; none were added.
A delisting summary is presented in Section A [PDF 218K]. Delisting is discussed in detail in Section J [PDF 428K] and delisting tables are included in Section M [PDF 329K].
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Which specific waters were added or removed from Category 5?
As described in the previous item, there were many delistings. Detailed delisting tables are included in Section M [PDF 329K].
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What is the condition of Ohio's waters?
Human Health Use (Fish Tissue)
The 2010 human health use (fish tissue) results are not appreciably different from the 2008 results. Fish tissue data were assessed in nearly every major (8 digit) hydrologic unit in Ohio. Between one quarter and one third of the watershed assessment units assessed for human health use are in attainment of that use. PCB contamination, primarily a result of historic industrial sources and old landfill discharges, is the cause of most of the human health use impairments. Mercury is the second leading cause of human health use impairments after PCBs.
Recreation Use
Less data are available for analysis because point source dischargers are not yet monitoring using E. coli, but this situation should improve beginning in the 2012 report. Approximately 10,400 E. coli bacteria records were used in the 2010 analysis.
Data were available for about one-third of the watershed assessment units watersheds in the state; about two-thirds are not assessed. Of the third that have data, only 13% attain the recreation use (the swimmable goal of the Clean Water Act) and the remaining 87% did not. Looking at data at individual sites instead of the watershed units, 44% of all the sites on the most heavily used primary contact recreation waters (Class A) are in attainment of the recreation use.
For the large rivers, data are available for 15 of 38 units (40%). Of these, two (Paint Creek and Walhonding River) support the recreation use (13%) while the remaining 13 (87%) do not. However, about one-half of the non-attaining units have an index score of 89 or higher, indicating that they are close to supporting the use. The lower Tuscarawas River (Stillwater Creek to the mouth) had the lowest index score (38) followed by the Cuyahoga River (45).
Aquatic Life Use
Most impairment of the aquatic life use is related to modification of the landscape involving agriculture and urban development. The top five causes of impairment for the aquatic life use for the period 1999 through 2008 are siltation/sediment, nutrients, habitat modification, hydromodification, and organic enrichment / dissolved oxygen (DO). These types of impairments have the most impact on smaller streams. Nearly all of the 999 (of 1538) impaired watershed units had at least one of these causes contributing to impairment and many had three or more of the top five causes listed.
The upward trend in full attainment of the aquatic life use in both watersheds and larger streams continues. In general, large rivers in Ohio are meeting aquatic life use goals at a much higher percentage than smaller streams. Ohio’s large rivers (the 23 rivers that drain more than 500 square miles) continue to show improvement. The current large river full attainment statistic now stands at 93.1%, while the average watershed score is 58.5 and the principal streams and large rivers statistic stands at 70.8%.
| Aquatic Life Use Attainment - 2010 |
| Average Watershed Assessment Unit Score |
Attainment Percentage of Large Rivers |
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The significant increase in full attainment for the large rivers from the 2008 to the 2010 cycle is largely because of new 2007 and 2008 intensive assessments of the Little Miami River, Mohican River, Walhonding River, Great Miami River (upper), Licking River, and Cuyahoga River. All reflected considerable improvement over prior surveys conducted during the mid- to late-1990s, and many more miles of full aquatic life attainment were identified. Aiding this highly positive trend was the exclusion of two large rivers (Great Miami River and the Maumee River) because available data exceeded 10 years in age and are not considered to be current. Using the most recent data from all the large rivers irrespective of age, the attainment statistic stands at 79.6%, essentially achieving the “80 by 2010” goal. Using either statistic, the “80 by 2010” goal has been met for the large river assessment units in Ohio.
Public Drinking Water Supply Use
A key challenge for increasing the number of PDWS assessments continues to be limited water quality data at drinking water intakes. Ohio EPA has now incorporated PDWS beneficial use sampling in the watershed surveys and within the next few reporting cycles the percent of assessed PDWS waters should continue to grow from the 39% reported on in 2010.
Elevated nitrate continues to be the cause of impairment for three large river assessment units on the Maumee and Sandusky Rivers. Twenty six waters were also placed on the watch list due to elevated nitrate in finished water and source waters, located primarily in the northwest and central portions of the state. The primary sources of elevated nitrate are nonpoint source runoff from agricultural land use and home/commercial fertilizer application, failing septic systems and unsewered areas, and wastewater plant discharges.
Atrazine is a pesticide of concern in Ohio drinking water sources and is the cause of impairment in source waters for three Ohio communities located in the southwestern portion of the state. The primary source of atrazine in these watershed is nonpoint source runoff from agricultural land use.
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For more information, contact:
Trinka Mount
TMDL Coordinator
Ohio EPA, Division of Surface Water
trinka.mount@epa.state.oh.us
(614) 644-2146