In 2015, Chinese government launched an ambitious regulation "Action Plan for Water Pollution Prevention and Control". In which, according to the central government, the "black and smelly river" in provincial cities will be eliminated by the end of 2017, will be controlled within 10% in prefecture-level cities by the end of 2020, and will be cleaned up in all cities by the end of 2030. This is a pretty big thing, we heard governmental actions often, and do notice the government have put a lot of effort on it.
As I live in Guangzhou -- the capital city of Guangdong province, which should have no black and smelly rivers by the end of this year according to the regulation, we are curious if this is really going to happen.

According to the "Guidelines for black and smelly river control", the black and smelly rivers are distinguished by 4 parameters: Transparency, Dissolved Oxygen, ORP, and Ammonia, here is the original content:

I translated as below:

Standerd method:

@shizi did lots of scopings related with each parameters' meaning and the methods. Since it is too hard to translate to English, I just put some of the results we found, in order to monitor this 4 parameters. The links might be useful to whom also want to monitor the river (and it is from Taobao).

1. Transparency

it is affected by the sun height, suspended matter and plankton.

• Secchi Disk, 7 USD or 16 USD with the 30 meter band tape. Put the black and white disk into the water, until you can not see the disk, read the length of the tape.

• transparency tube, 70 USD when the river is shallow, it's better do use this.

2. Dissolved Oxygen (DO)

This is regarded as river's self-purification ability, and related with the concentrations of organic matters, ammonia, as well as pressure, temperature, etc. There are many ways to detect DO's concentration

1. Cheapest way is chemical method, read color index, with less then 5 USD, you can test 50 times the detect scale is mostly 0-1-2-3-...
2. Also titration method, 30 USD, 50 times this method is accurate then color reading, the detect scale is 0-0.2-0.4-0.6...
3. Electrode method. easy to read the number, but expensive. normally need to preheat the machine. the most famous Chinese brand is LEICI (or INESA), costs 280USD including the probe, solution, membrane, etc also Taiwan AZ

3. ORP or Oxidation-Reduction Potential

this is a comprehensive parameter, related with many other parameters, especially pH, and DO. It has a great affect to the river microbe. When it get lower, microbial activities will change, many side effect will happen. All the testing tools we found are using the electrode way, the price vary, we currently don't know the difference.

• Taiwan AZ's pen type ORPmeter costs around 50 USD
• Taiwan AZ's handhold type ORPmeter costs 200 USD
• many ORPmeter also test ph at the same time

4. Ammonia

ammonia can lead to water eutrophication, is one of the main oxygenate pollutants, have big affect to fish and some aquatic organisms.

• Chemical method is the cheapest, 5 USD for 50 times

• Nessler reagent photometric method, 240 USD, also need to buy membrane in order to filter, and syringes