Admin Order 58-12-14 - Laserfiche WebLink

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SECTION 4 Water Quality Eualuatiou As part of the process to implement the new rules, DEQ required UIC systems (i.e., drywells) to be registered with DEQ by December 31, 1999 (with amnesty for public systems until December 31, 2000). Stormwater UICs are prohibited unless they can be shown to meet criteria for being regarded as "exempt ", "authorized by rule ", or "authorized by a permit ". These three categories of allowable stormwater UICs are described in more detail as follows: Exempt — Stormwater UICs that are exempt include single residential roof drains and footing drains receiving only rainwater. Authorized by Rule — Municipalities may apply to have stormwater UICs "rule authorized" if the following criteria are met: a) No other waste is mixed with the stormwater. b) Stormwater runoff is minimized. c) No other disposal option is appropriate. An appropriate method shall protect groundwater quality and may consider management of surface water quality and watershed health issues. d) No domestic drinking water supply wells are present within 500 feet. e) No public drinking water supply wells are present within 500 feet or the 2 year time -of- travel whichever is more protective. f) No soil or groundwater contamination is present. g) The wells are not deeper than 100 feet and they do not discharge into groundwater or below the highest seasonal groundwater level. h) A confinement barrier or a natural or engineered filtration medium is present between the base of the injection system and the highest seasonal groundwater level and prevents contaminants from reaching groundwater, or the owner or operator implements best management practices that prevent drainage into the injection system in the event of an accidental spill. (DEQ has suggested that they would like to see 10 feet of separation between the bottom of the drywell and the high groundwater). i) Design and operation prevents accidental or illicit disposal and temporary blocking is available. Authorized by Permit - Municipalities may apply to have their stormwater UICs covered by a water pollution control facilities (WPCF) permit. If UICs are not exempt or can not be rule authorized, the permit would provide a mechanism for the municipality to work with DEQ to develop a plan for these UICs, which could include retrofitting the UICs so that they meet "rule authorization" criteria or developing a plan for decommissioning UICs that can not be rule authorized. A WPCF permit would likely include significant requirements for monitoring. The County evaluated their public drywells and had them registered with DEQ by December, 2001. The City evaluated their public drywells and had them registered with DEQ by November 2001. None of the City or County public drywells met the criteria for being exempt. An initial study conducted by the City as part of the UIC registration process also showed that only 16 (of 78) wells were not likely to be rule authorizable. However, based on more recent DEQ 0:\25695978 Eugene RR -SC Final Basin P1an\Master P1anTINAL 2- 2010\Master_Plan 3- 11- 10_FINAL_ Word _Version.doc 4-3