émissaire

13:58 Jul 28, 2016 

Why make life difficult by omitting the names of the towns and rivers and substituting strange parentheses? If you're that bothered about confidentiality, use fictitious names!

13:39 Jul 28, 2016 

The parentheses do make it tricky, but I don't think it's saying 'ville émissaire' but ''fleuve émissaire': that monitoring is being carried out in river X downstream from town X i.e. in the outflow (or emissary or effluent) river.

13:21 Jul 28, 2016 

the original posting was: 'Les apports en azote, phosphure et chlorure ont ete suivis... comme chaque annee depuis 1963, aux embouchures des principaux affluents du xxx( le [river] amont, etc....) ainsi que dans le [river] a l'aval de [town] ([river] émissaire...'
You appear to have misses a bracket (before [river}) that is very important.

13:17 Jul 28, 2016 

Effluent: something that flows out of: as A: an outflowing branch of a stream or lake b: waste material (as smoke, liquid industrial refuse, or sewage).
Source: Merriam Webster

13:12 Jul 28, 2016 

I don't see what "[town] [river] émissaire" could mean. What does the French say?

12:54 Jul 28, 2016 

We can't (at least not in English) talk about pollutants downstream of an "emitting" town (if I understand your parentheses correctly). It's a nice shorthand in FR, but just doesn't work in EN, so you need to say something along the lines of "into the river downstream of the town generating/creating/producing the nitrates/phosphates/chlorates..." or similar.