Monitoring the quality of your wastewater and taking corrective action where necessary, protects the health and the safety of the people and the environment in your vicinity.

By Janice McNally

Starting a water monitoring

programme

First, the amount of water that flows through a wastewater system needs to be measured with a flow meter, to calculate the amount of water flowing through the system.

Water users can start monitoring the basic requirements of water quality( see Table 1) and progress to adding more substances / tests to their monitoring schedule.

The most common, modern method municipalities use to test physical and chemical substances in water is photometric, using a modern electronic instrument known as a photometer. These have step-by-step instructions and can be performed by a layman. Many photometers can test for between three and 70 different substances. It is a good idea to purchase a photometer that has additional parameters, so your requirements can be met once the water programme develops. Should you wish to do additional tests, you can then purchase the chemical reagents where needed. Photometers are available in handheld, benchtop, and in-line versions. Larger district municipalities often have an in-house water testing laboratory with a bench-top photometer / spectrophotometer. Smaller handheld photometers are often used in the field and in rural areas. However, many municipalities still use the long-standing visual Lovibond ® comparator system.

Faecal contamination is also a vital substance to measure in wastewater. E. coli bacteria are the common microbiological parameter measured. A quick test to reveal the presence /

100 to 1 000 cubic metres pH Electrical conductivity( mS / m) Faecal coliforms( per 100ml) Chemical oxygen demand( mg / l) Ammonia as nitrogen( mg / l) Suspended solids( mg / l) Phosphate( mg / l)

1 000 to 2 000 cubic metres pH Electrical conductivity( mS / m) Faecal coliforms( per 100ml) Chemical oxygen demand( mg / l) Ammonia as nitrogen( mg / l) Nitrate / nitrite as nitrogen( mg / l) Free chlorine( mg / l) Suspended solids( mg / l) Ortho-phosphate as phosphorus( mg / l)

* Source: WISA ** Source: Water Quality Association( www. wqa. org) *** Source: US Environmental Protection Agency absence of bacteria in water can be performed using an ATP luminometer. More detailed investigations will require a test kit and incubation for 12 – 48 hours.

Some municipalities perform some of these basic tests themselves on a regular basis and contract out the less frequent testing to a water laboratory for analysis. Doing the analysis oneself ensures a faster response time. According to the Lovibond ® Tintometer ® White Paper, in-house water sampling contributes to huge savings in today’ s industry.

Records of the water monitoring programme and corrective action taken need to be kept.

Corrective action plans need to be set up and put in motion by the addition of water treatment chemicals, so that clean water can be released back into the environment.

Remember the three R’ s: Read, Record, and React. u

Water Quality Fact Sheet * – pH Water Quality Fact Sheet * – EC & TDS Water Quality Fact Sheet * – Faecal coliforms Water Quality Fact Sheet ** – Ammonia Water Quality Fact Sheet *** – Screening & grit removal Water Quality Fact Sheet *** – Phosphorus Water Quality Fact Sheet * – Nitrate & nitrite Water Quality Fact Sheet * – Free chlorine networking contributor innovations industry debate environment infrastructure municipalities

Water Sewage & Effluent January / February 2018 29