1. The Iowa Water Quality Standards: an overview Nutrient Science Committee June 13, 2007 John Olson Watershed Monitoring & Assessment Section Iowa DNR

2. Background Iowa’s first WQS were developed in the late 1960s for inter & intra-state waters; first approved by EPA in 1971 Iowa’s WQ Standards (aka, Chapter 61, Iowa Administrative Code) are available on the web: http://www.iowadnr.com/water/standards/files/chapter61.pdf The most recent surface water classification document is available at the following web location: http://www.iowadnr.com/water/standards/files/chapter61.pdf The standards have changed considerably over the years, especially in the last three years or so.

3. Background (continued) Clean Water Act Section 303(c) requires states to develop & implement WQS WQ Standards have three components: 1.a designated beneficial use (e.g., protection of aquatic life, primary contact recreation, and/or drinking water uses) 2.criteria to protect the designated use 3.anti-degradation policy (the level of water quality necessary to protect the existing uses will be maintained and protected)

4. Framework of Iowa’s Beneficial Uses general uses: includes uses for livestock & wildlife watering, non-contact recreation, crop irrigation, industrial, agricultural, & domestic water uses; protected by narrative criteria; the base-level of protection for all Iowa surface waters: designated uses (protected by numeric criteria): –Class A waters: designated for body-contact recreation uses (e.g., swimming or wading) –Class B waters: designated for aquatic life uses –Class C waters: used as a raw water source of a potable water supply –Human Health: designated for fish consumption

5. General WQ Criteria Apply to all surface waters at all places & times Are primarily narrative criteria; for example: Such waters shall be “free from”: –point-source discharges that cause sludge deposits –wastewater discharges or agricultural practices that produce: nuisance levels of floating debris, oil, grease, scum, etc. objectionable color, odor or other aesthetically objectionable conditions (my personal favorite) conditions acutely toxic to human, animal or plant life substances in quantities that would produce undesirable or nuisance aquatic life »(continued)

6. General WQ Criteria (concluded) Turbidity of receiving water shall not be increased by more than 25 NTUs; Acceptable levels of TDS and constituent cations and anions will be established on a site-specific basis; The E. coli content of a water entering a sinkhole or losing stream segment shall not exceed a geometric mean of 126 organisms/100 ml or a sample maximum of 235 organisms/100 ml; no new wastewater discharges allowed on such watercourses.

7. Class A waters: water-based recreation Class A1: primary contact recreational use: considerable risk of ingesting water (e.g., swimming) Class A2: secondary contact recreational use: minimal risk of ingesting water (e.g., wading) Class A3: children’s recreational use: recreational uses by children are common; primarily in urban or residential areas Class A uses: –Can apply to all types of surface waters –Apply from March 15 through November 15 –Bacterial criteria for Class A1 and Class A3 criteria are identical; Class A uses are also protected by pH criteria

8. Class B waters: protection of aquatic life Class B(LW): warmwater lakes & wetlands ------------------------------------------------------------------------------------------------------------------------------------------------------------------- Class B(WW-1): warmwater rivers/streams (& on-stream impoundments) with game fish Class B(WW-2): warmwater streams w/o game fish but support non-game fish; perennial flow Class B(WW-3): warmwater streams w/o game fish but support non-game fish in perennial pools* –*intermittent watercourses are classified for general uses only -------------------------------------------------------------------------------------------------------------------------------------------------------------------- Class B(CW1): coldwater streams supporting trout Class B(CW2): very small coldwater streams w/o trout but have other CW aquatic life --------------------------------------------------------------------------------------------------------------------------------------------------------------------- –Class B criteria include a variety of conventional and toxic pollutants

9. Protecting Human Health Class C (drinking water uses): lakes or rivers used as a source of raw water for a potable water supply –criteria include nitrate, pesticides (e.g., atrazine) toxic metals, and toxic organic compounds Human Health: lakes, rivers, or streams in which fish are routinely harvested for human consumption; can be added to the Class B(WW-1), Class B(CW1), Class B(LW), or Class C designations –criteria include toxic metals (e.g., mercury), pesticides (e.g., chlordane), and toxic organic compounds (e.g., PCBs)

10. Protecting waters with exceptional quality High Quality (HQ) Waters: waters with exceptional recreational and ecological importance that have exceptionally better chemical water quality than required by existing numeric WQ criteria. High Quality Resource (HQR) Waters: waters with exceptional recreational and ecological importance that possess unusual/outstanding physical, chemical, or biological characteristics that warrant special protection. –HQ and HQR are not associated with specific numeric criteria but are related to the antidegradation policy

11. Antidegradation Policy: the level of water quality necessary to protect the existing uses will be maintained and protected implementation: ???

12. Examples of Use Designations Raccoon River at Des Moines –from Polk/Dallas county line to confluence of N. & S. Raccoon rivers [approximately 10 miles] –Class A1, B(WW-1), C, HH, HQR Hickory Grove Lake, Story Co., S24, T83N, R22W –Class A1, B(LW), HH Big Creek Lake, Polk Co., S26, T-81N, R25W –Class A1, B(WW-1), HH Lake LaVerne, Story Co., S4, T83N, R24W –Class B(LW), HH

13. Iowa’s Specific WQ Criteria The Iowa WQ Standards contain numeric criteria to protect all types of Class A, B, C, and Human Health uses State numeric criteria are based on EPA [304(a)] guidance and have been approved by EPA Examples of these criteria include bacteria, pH, DO, temperature, toxic metals, pesticides, toxic organics, ammonia, and nitrate (drinking water MCL only) No criteria exist for nutrient parameters, for chlorophyll, or for ambient water clarity EPA published 304(a) documents for nutrient criteria in lakes and rivers/streams in 2000

14. The Rebuttable Presumption A recent addition to the Iowa WQ Standards Thus far, applied to rivers and streams Historically, Iowa has used a “bottom-up” approach to applying designated uses to streams & rivers The rebuttable presumption is a “top-down” approach that presumes all perennially flowing rivers/streams can support the highest level of contact recreation and aquatic life (I.e., Class A1,B(WW-1)). Use attainability analyses (UAAs) will be needed to rebut the presumed uses and to arrive at the appropriate set of designated uses.

15. Changing WQ Standards Involves, at least, the following: –the state’s rulemaking process (draft rule preparation, public meetings/comments, responsiveness summary, approval by EPC) –approval from U.S. EPA (a current hot topic) –can take from a few months to several years –changing use designations is very tricky and involves potentially huge commitments of time and resources