Pink water

Pink water and red water (waste) are two distinct types of wastewater associated with TNT. Red water is produced during manufacture. Pink water is produced from equipment washing processes after munitions filling or demilitarization operations, and as such is generally saturated with the maximum amount of TNT that will dissolve in water (about 150 ppm.) However it has an indefinite composition that depends on the exact process; in particular, it may also contain RDX if the plant uses TNT/RDX mixtures, or HMX if TNT/HMX is used.

Pink water is actually colourless at the time of generation; the colour is produced by photolytic reactions under the influence of sunlight. Despite the name, pink water is not necessarily any lighter in colour than red water; the colour depends mainly on duration of solar exposure. If exposed long enough, "pink" water will become dark brown.

Because of the toxicity of TNT, discharge of pink water to the environment has been prohibited in the USA and many other countries for decades, but ground contamination may exist in very old plants. However, RDX and tetryl contamination is usually more of a problem because TNT has very low soil mobility.

References

# [http://www.globalsecurity.org/military/systems/munitions/explosives-env.htm Explosives & the Environment] at GlobalSecurity.org
# [http://books.google.com.au/books?id=BD3c7FN4x5YC&pg=PA39&lpg=PA39&dq=%22red+water%22+tnt&source=web&ots=mJ8bSKkqJL&sig=I9nPLNW7fx97JPNruHMtsEOwZlc&hl=en Toxicity and Metabolism of Explosives] (by Jehuda Yinon), referenced at Google Books.