The most commonly available electronic sensors for collecting water quality data seem to be:
- Dissolved Oxygen
- ORP (Oxidation-Reduction Potential)
None of these things directly test for the presence or absence of particular chemicals or contaminants.
There are also ion-selective electrode-based sensors that detect the presence of specific chemical ions. These are a lot more expensive then the other sensors -- ranging from $250 at the low end to thousands of dollars at the highe end. Common ones seem to be:
Which of these measures are likely to be worth collecting for communities affected by oil/gas industry related pollution?
Aimless research suggests that oil spills cause a lowering of disoolved oxygen, increased temperature, and increased pH (http://www.bioline.org.br/request?ja04029), that oil is less conductive than water and so significant amounts amounts of oil will lower conductivity (https://archive.epa.gov/water/archive/web/html/vms59.html) but that there are lots and lots of things in refinery wastewater from different parts of the processes and some of them might increase and some might decrease conductivity (https://savetexaswater.org/bmp/industrial/doc/Refining_Water_Best_Practices.pdf)
But I don't know what I'm doing or talking about and would really appreciate insight from people who know more about the oil and gas industry or water quality monitoring.
It's nice to know what kinds of data are worth focusing on collecting, but it's also nice to be able to give people who are interested in community data-collection a clear story about the relationship between the information they are collecting and the pollutants/contamination they are worried about (even if the story isn't as simple as "this measurement means we have this chemical"....)