FINAL ENVIRONMENTAL IMPACT STATEMENT 3.14 Water Quality and Hydrology Communities depend on a reliable supply of clean water for domestic use, agriculture, industry, and recreation. Fish and many wildlife species depend on clean water habitats to live. In urban areas, pollutants that wash off roadways during storms contribute to poor water quality in rivers and streams. Pollutants from roadways typically include fuel, oil, grease, and other automotive fluids; heavy metals such as copper and zinc; and small particles from erosion or road sanding which can temporarily make waterways more turbid (cloudy). The design and placement of roadways and stormwater systems can affect how stormwater is treated and released into the environment. Placing structures such as bridge piers or roadways in a waterway or its floodplain may increase the height of floods during storm events. Although an individual road or structure may be small in relationship to the volume of a waterway, collectively, all roads, What is the difference structures, and other developments between water quality constructed along a river can have a and hydrology? dramatic effect on the severity of floods. For this reason, construction in streams In this FEIS, hydrology refers to the and rivers or in their floodplains is flow of water—its volume, where it drains, and how quickly the flow rate strictly regulated, and must take into changes in a storm. Water quality refers account any incremental contribution to the characteristics of the water—its toward worsening flood conditions on temperature and oxygen levels, how clear the waterway. it is, and whether it contains pollutants. This section examines the potential effects of the CRC project alternatives on both water quality and hydrology, and relates these potential effects to the existing conditions in the waterways and surrounding areas. A comparison of impacts from the LPA and DEIS alternatives is summarized in Exhibit 3.14-4. A more detailed description of the impacts of the DEIS alternatives on water quality and hydrology is in the DEIS starting on page 3-377. Groundwater and aquifers are discussed in greater detail in Section 3.17, Geology and Soils of this FEIS. This section also discusses a conceptual stormwater treatment design for the LPA that has been developed for analysis purposes and to advance discussions with agencies on regulatory approvals. This design meets regulatory criteria. Agency coordination will continue through the development of the final stormwater design, to be completed as part of future permitting. This section addresses impacts in the main project area, at the Ruby Junction Maintenance Facility, the Steel Bridge, and at casting and staging areas. See Chapter 2 for a map of these areas. More detailed and technical discussions of the information presented in this section can be found in the CRC Water Quality and Hydrology Technical Report, included as an electronic appendix to this FEIS, and the CRC Stormwater Management Memorandum, included as an appendix to the Water Quality and Hydrology Technical Report. Water QUALITY AND HYDROLOGY EXISTING CONDITIONS AND ENVIRONMENTAL CONSEQUENCES • 3-333 COLUMBIA RIVER CROSSING 3.14.1 New Information Developed Since the Draft EIS Since publication of the DEIS, additional information has been gathered and analyzed in order to better assess and avoid adverse effects. The additional information includes: • The preparation of a Troutdale Sole Source Aquifer (TSSA) report that confirms previous assumptions about existing conditions and potential project impacts. For further information in regards to potential effects of the project on the TSSA, refer to Section 3.17 (Geology and Soils). The TSSA report is also included as Appendix E of the Hazardous Materials Technical Report. • More information on existing conditions, developed through field work, research, and agency coordination. In addition to new information developed since the DEIS, the FEIS includes refinements in design, impacts and mitigation measures. Where new information or design changes could potentially create new significant environmental impacts not previously evaluated in the DEIS, or could be meaningful to the decision-making process, this information and these changes were applied to all alternatives, as appropriate. However, most of the new information did not warrant updating analysis of the non-preferred alternatives because it would not meaningfully change the impacts, would not result in new significant impacts, and would not change other factors that led to the choice of the LPA. Therefore, most of the refinements were applied only to the LPA. As allowed under Section 6002 of SAFETEA-LU [23 USC 139(f )(4)(D)], to facilitate development of mitigation measures and compliance with other environmental laws, the project has developed the LPA to a higher level of detail than the other alternatives. This detail has allowed the project to develop more specific mitigation measures and to facilitate compliance with other environmental laws and regulations, such as Section 4(f ) of the DOT Act, Section 106 of the National Historic Preservation Act, Section 7 of the Endangered Species Act, and Section 404 of the Clean Water Act. FTA and FHWA prepared NEPA re-evaluations and a documented categorical exclusion (DCE) to analyze changes in the project and project impacts that have occurred since the DEIS. Both agencies concluded from these evaluations that these changes and new information would not result in any new significant environmental impacts that were not previously considered in the DEIS. These changes in impacts are described in the re-evaluations and DCE included in Appendix O of this FEIS. Relevant refinements in information, design, impacts and mitigation are described in the following text, including a revised conceptual stormwater treatment design. 3.14.2 Existing Conditions The surface water features studied for the CRC project are determined by the potential for water quality and hydrology impacts to these features from the project. Four major surface water features may receive stormwater runoff from the LPA: the Columbia Slough, the Columbia River (which includes the North Portland Harbor), Burnt Bridge Creek, and Fairview Creek. For the surface water features located in the main project area, their locations and designated watersheds are identified in Exhibit 3.14-1. 3-334 • CHAPTER 3 Water QUALITY AND HYDROLOGY 9 9 Y A W H G I B E H R N IE 68TH 63RD MINNEHAHA S N F H R U JO I T T V S A S L E L M E Y JA T S 54TH N ROSS L O C Burnt Bridge Creek N I L !` H T Watershed 5 1 49TH 45TH B u r n t B r 44TH i d g e LO 39TH C WE R RIV r ER e e A¬ k N A M F F 33 U RD A A I K B M U L O Q LO C WE D R N N R I I A VE A R R M G F A L K FOU N RT H PLAIN O S P N M Y I L A S O W C D 20 N TH I A L O R R E B V 18TH U O C N 15TH A V P T O R MCLOUGHLIN R O F T 13TH N 9 9 O Y T A W C G H FINAL ENVIRONMENTAL IMPACT STATEMENT T G I N B D H I E R N H N IE 68TH A S E A V R B W R Exhibit 3.14-1 E MILL PLAIN 8TH S E 63RD Main Project Area Watersheds and Water Features R MINNEHAHA S N 9 F 9 H R Columbia River Y U JO A 6TH I T T W EVERGR EEN S V H A S G I L E B L H M E E R Y JA Watershed N IE 68TH T S D 54TH R O N ROSS L F O D 63RD C Burnt Br5iTdge Creek N H N I L !` A MINNEHAHA H L T Watershed S B 5 N 1 F H R 49TH U JO I T C T V S A S L E 45TH L O M E Y B JA u r n L T t S B E 44TH r HOUS U 54TH i UMBIA CdOgL N ROSS E L e V O M E 39 R C Burnt BridLge Creek TH OW C G N I ER R L !` R ?£ r B IV E E H R e E T Watershed e N 5 COLUMBIA 1 I k 49TH A A¬ N 45TH A M F B u r F 33 U RD n A t A I K B B 44TH R r M i U d I L O Q g V C LO e WE D N N R E I R L 39TH I A O C VE A W R R E R M R G F RI r VE A R e L e K A¬ k FOU N RT H PLAIN O N S A P M N M Y I L F A F S M 33 O U RD W A C A A I D 20 R N TH I K B I A N L M E O U R R L E B V 18TH O U Q O LO C C W D N E 15TH A N N R I V R P A IV A T E O MCLO R R R UGHLIN M R O G F F T A 13TH N L K O T C G T N D I N FO H U A N RT S H PLA E A IN R O V B S W R P E MILL PLAIN N S M 8T Y H I L E A S O R W D C D 20 N TH I Columbia River A N L N 6TH A O EVERGREEN R R L E B V o 18TH T U Watershed O R C r D N 15TH A O V R P t P T O O R MCLOUGHLIN h F R O 5 D F TH N T 13TH A N P L O B T o C G T r C N D I t N H l O A S a E A R n V L B d W R HOUSE E H BIA MILL PLAIN U a OLUM C S r b o r 8TH E E M VE R R ?£ GR B E Columbia River EN 6 I COLUMBIA TH EVERGREEN A Watershed MARINE D R R O F I 5TH D V N E A L R C B O L EU MA BIA HOUS N R U COLUM INE IO EV M ER ?£ N GR B EE I A COLUMBIA N R C D I N N C o V A O L L E T o 3 U l R M R r 3 O B u P t I M h A P R m L o r D b K t l a n d MA H a r b o r RI i NE a !` MARINE S l C o OL U u U MB Columbia Slough N D IA g IO N N N A L T o h R r O P t h R C C P E O o o LU l 3 r M Watershed 3 B V u I M t l A R a n m L D d N H a r b o r b K E i a D S !` MARINE l CO o LUM u Columbia Slough BIA g h R E Watershed U V N IO N N E D C C OL o UM l 3 B u 3 IA M R m L D b i K a !` S l CO o LUM u Columbia Slough BIA g h E CO R T LU A E MB Watershed T V IA S N R E E E C D T O T N L D I U R A M B LOMBARD 3 3 T IA S R Exhibit 3.14-1 E T Main Project Area and Hydrology N ² D Main Project Area Project Footprint I R 0 LOM0.2B5 ARD 0.5 3 Watershed 3 Miles E CO T LU A MB T IA S Analysis by J.