caa a22 4500 469030062 CHVBK 20180323132741.0 cr unu---uuuuu 170328e19920801xx s 000 0 eng 10.1007/BF00418012 doi (NATIONALLICENCE)springer-10.1007/BF00418012 Past and present water-quality conditions in the Hanford Reach, Columbia River [Elektronische Daten] [C. Becker, Robert Gray] Twelve water quality variables from upstream and downstream locations in the Hanford Reach of the mainstem Columbia River, southcentral Washington, were compared statistically for the two time periods 1951 to 1953 and 1986 to 1988. During the 1951 to 1953 period, beta radioactivity and, most likely, water temperatures in the Hanford Reach were significantly higher downstream than upstream, while dissolved oxygen and sulfate were significantly lower. The increased beta radioactivity and temperature downstream were due to the discharge of cooling water from five single-purpose production reactors then operating on the Hanford Site. The last production reactor closed in January 1971. During the 1986 to 1988 period, beta radioactivity and water temperatures were similar upstream and downstream, but nitrate nitrogen had become significantly higher downstream. Comparison of 1951 to 1953 with 1986 to 1988 showed, as expected, that beta radioactivity was much lower today, at essentially background levels. Phosphate in the Hanford Reach had decreased significantly over the 35 year interval, while biochemical oxygen demand, dissolved oxygen, and nitrate nitrogen had increased. These changes, while detectable statistically, were relatively small. Today, the quality of water in the Hanford Reach remains well within Washington State standards for Class A waters. Occasional low pH values, which appear to orginate upriver, violate these standards. Kluwer Academic Publishers, 1992 Becker C. of Pacific Northwest Laboratory, Earth and Environmental Sciences Center, 99352, Richland, Washington, U.S.A. aut Gray Robert of Pacific Northwest Laboratory, Earth and Environmental Sciences Center, 99352, Richland, Washington, U.S.A. aut Environmental Monitoring and Assessment Kluwer Academic Publishers 22/2(1992-08-01), 137-152 0167-6369 22:2<137 1992 22 10661 https://doi.org/10.1007/BF00418012 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00418012 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Becker C. of Pacific Northwest Laboratory, Earth and Environmental Sciences Center, 99352, Richland, Washington, U.S.A aut NATIONALLICENCE 700 1- Gray Robert of Pacific Northwest Laboratory, Earth and Environmental Sciences Center, 99352, Richland, Washington, U.S.A aut NATIONALLICENCE 773 0- Environmental Monitoring and Assessment Kluwer Academic Publishers 22/2(1992-08-01), 137-152 0167-6369 22:2<137 1992 22 10661 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer