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Oregon's 2004/2006 Integrated Report and Section 303(d) list of water quality limited <br />waters were finalized and submitted to the U.S. Environmental Protection Agency <br />Region 10 office on May 23, 2006. The final report reflects changes made in response to <br />public comments received in Fa112005. The 2004/2006 Section 303(d) list became <br />effective on September 29, 2006 when EPA approved this list. The report database <br />updates the 1998 and 2002 databases and 303(d) lists. DEQ can "de-list" or remove a <br />waterbody from the 303(d) list when EPA has approved water quality management plans <br />and Total Maximum Daily Loads (TMDL) determinations .for listed segments or streams. <br />TMDLs outline how much pollution a water body can safely handle and still support <br />beneficial uses. <br />Since 2002, Amazon Creek has been listed as "water quality limited" (303(d) list) for <br />arsenic from river mile O to 22.6 (mouth to Martin Street crossing in southeast Eugene). <br />This listing was based on water quality data submitted by the City of Eugene Department <br />of Public Works (see Appendix.l). Arsenic is a naturally occurring element. Increased <br />levels of arsenic in water and soil are a result of leaching from arsenic=rich geologic <br />layers into surface and ground water. The EPA has classified arsenic as a known <br />carcinogen. <br />Water quality standards consist of numeric and narrative criteria. Numeric criteria are <br />scientifically derived ambient concentrations developed by the EPA or states for various <br />pollutants of concern to protect human health and aquatic life. The EPA standards for <br />drinking water fall into two categories -Primary Standards and Secondary Standards. <br />Primary Standards are based on health considerations and are designed to protect people <br />from pollutants including toxic chemicals. Arsenic is classified under the Primary <br />.Standards, with a maximum of 2.2 ng/L ambient water concentration for consumption of <br />both contaminated water and fish (OAR Table 20, Appendix 2). <br />Additional considerations in Oregon's water quality standards pertinent to the listing of <br />Amazon Creek for arsenic are the following: <br />OAR 340-41-445(2)(p}(A): Toxic substances shall not be introduced above natural <br />background levels in the waters of the state in amounts, concentrations, or combinations <br />.which may be harmful, may chemically change to harmful forms in the environment, or <br />may accumulate in sediments or bioaccumulate in aquatic life or wildlife to levels that <br />adversely affect public health, safety, or welfare; aquatic life;. wildlife or other designated <br />beneficial uses; <br />OAR 340-41--445(Z)(p)(B): Levels of toxic substances shall not exceed the criteria <br />listed in Table 20 which were based on criteria established by EPA and published in <br />Quality Criteria for Water (198b), unless otherwise noted; <br />The Willamette Basin TMDL project was begun by DEQ in early 2000 and was designed <br />to address the 1998 303(d) listed waterbodies for parameters that do notmeet water <br />quality criteria. As stated previously, the Willamette Basin TMDL was approved by the <br />EPA on .September 29, 2006. The 2002- arsenic and lead 303(d) listings for Amazon <br />