** SciDev SDV.AX rises as much as 6.1% to A$0.350, highest since September 24

** Water treatment solutions provider wins A$19.5 million ($12.7 million) contract from McMahon Services Australia (NT)

** Contract for construction of treatment plant for contaminated groundwater from uranium mining at former Rum Jungle Mine near Darwin

** About 2.7 million shares traded, ~19.3x the 30-day avg, in stock's busiest session since August 27

** SDV last up 3%, trims YTD losses to ~41%

($1 = A$1.5389)

(Reporting by John Biju in Bengaluru)

((John.Biju@thomsonreuters.com;))