Department of water affairs and forestry technical guidelines for the development of water and sanitation infrastructure

17.3Laboratories, offices and other facilities

Laboratory or on-site analysis of water may be performed as a means of plant and system control or adjustment and as a periodic check on water quality. Routine testing of water is designed to establish that the water is aesthetically acceptable and hygienic. These tests may be carried out with relatively simple equipment, titrations, colour comparison or simple robust instrumentation such as pH measurement.

Any water supply scheme such as a borehole or a river pump station where chlorine is added to the water should be provided with a chlorine test kit and the necessary reagents. The recommended equipment is a Lovibond comparator with a chlorine disc B/40A and DPD tablets.
On a small scheme where lime is added a test kit such as that for chlorine, but with a pH disc and reagents should be provided. Alternatively a simple robust PH meter may be used.
Suitable testing equipment and testing frequency for a small water treatment plant that produces <1M1/d are indicated in the table below:

PARAMETERS	EQUIPMENT	FREQUENCY	REMARKS
PH	PH meter	Daily	If lime is added
Turbidity	Turbidity meter	Daily	If flocculants are added
Colour	Colour comparator	Daily
Chlorine: Total residual Free residual	Chlorine comparator	Once a day At least twice a day	When gas chlorine is used. When chlorine tablets or solutions are used.
Flocculation	Laboratory jar stirrer	When necessary	When replacing flocculant with a new one or when the nature of the raw water changes
Conductivity TDS E-coli Total hardness Calcium hardness Magnesium hardness Total alkalinity Sulphates Chlorides Fluorides Nitrates Iron Manganese	These tests can be contracted out or performed by a nearby larger facility.	In accordance with the water quality monitoring schedule.	Alternatively when there is pollution or suspicion of pollution in the area.

Note: Potable water should comply with SANS 241. See Chapter 9 for Water Treatment plants.
Suitable testing equipment and testing frequency for a water treatment plant which produces between 1M1/d and 5Ml/d s are listed in the table below:

PARAMETER	EQUIPMENT	FREQUENCY	REMARKS
PH	PH meter	Daily
Turbidity	Turbidity meter	Daily
Colour	Colour comparator	Daily
Chlorine: Total residual Free residual	Chlorine comparator	Once a day At least twice a day	When gas chlorine is used. When chlorine tablets or solutions are used.
E-coli	Incubator	Weekly
Conductivity	Conductivity meter	Daily
TDS	Weighing Balance/Calculations	Weekly
Total hardness Calcium hardness Magnesium hardness Total alkalinity	Titrations:Burettes	Daily
Stability test	Calculations	Daily
Flocculation test	Laboratory jar stirrer	When necessary	When replacing flocculant with a new one or when the nature of the raw water changes.
Sulphate Chlorides Fluorides Nitrates Iron Manganese	These tests can be contracted out or performed by a nearby facility.	Once a month or every two months.	Iron and Manganese may be analysed for on a frequent basis, where these are known to occur. Other specific metals may need to be determined when there are industrial or mining activities in the vicinity.

A complete laboratory as per list below should be provided for a water treatment plant which produces >5M1/d. Support laboratory equipment such as weighing balance, hot plates, filters, vacuum pumps, stirrers and burners will also be required.

PARAMETERS	METHOD/ EQUIPMENT	FREQUENCY	REMARKS
PH	PH meter	Daily
Turbidity	Turbidity meter	Daily
Colour	Colour comparator	Daily
Chlorine Total residual: Free residual	Chlorine comparator	Once a day At least twice a day	When gas chlorine is used. When chlorine tablets or solutions are used.
E-coli	Incubator	Daily
Conductivity	Conductivity meter	Daily
TDS	Weighing balance/ Calculations	Weekly
Total hardness Calcium hardness Magnesium hardness Total alkalinity	Titrations	Daily
Flocculation test	Laboratory jar stirrer	When necessary	When replacing flocculant with a new one or when the nature of the raw water changes.
Stability test	Calculations	Daily
Sulphates Chlorides Fluorides Nitrates Iron Manganese	Turbidity/ Gravimetric Titration Spectrometry Spectrometry Spectrometry Spectrometry	Weekly	Iron and Manganese may be analysed for on a frequent basis, where these are known to occur. Other specific metals may need to be determined when there are industrial or mining activities in the vicinity..

Laboratories, workshops and other facilities should be available at the time of scheme commissioning. Sufficient funds should be allowed in the project budget for the start up costs of these facilities.