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Have you checked your water quality lately?

By Linda Jackson on 16 March 2017

If you have been watching the Vaal dam levels you would have seen the amazing change over the last few months from severe water restrictions to possibly too much water.

The recent drought in the northern parts of the country and the current drought in the Cape areas should have brought about significant water savings in your facility. Just because these water restrictions have been lifted should not mean we go back to our old wasteful ways. If we could cope in a drought, surely we can cope in the good times and do our bit to use this precious resource responsibly.

As a food processor, the quality of the water is of utmost importance especially if used as an ingredient and for food contact surface cleaning.

What is the government doing?

Currently quality of water  is managed by means of comparing results obtained on water samples to a list of water quality standards included in the South African National Standards (SANS 241,Part 1&2 of 2015. Compliance to the stated water quality specifications are governed by the:

  • The Water Services Act (WSA) (Act No 108 of 1997), in accordance with Sections 9(1) and 73 (1)(j); and
  • Regulation 5 of Section 9 of the WSA (No.108 of 1997).

Compulsory National Standards

The Compulsory National Standards for the quality of potable water states:


Should a comparison of the results contemplated in sub-regulation (3) indicate that the water supplied poses a health risk, the water services institution must inform the Director-General of the Department of Water Affairs and Forestry and the head of the relevant provincial Department of Health and it must take steps to inform its consumers:

  • that the quality of the water it supplies poses a health risk;
  • of the reasons for the health risk;
  • of any precautions to be taken by the consumers; and
  • of the time frame, if any, within which it may be expected that water of safe quality will be provided.

That sounds good in theory but in practice service delivery issues plague the systems and we haven’t got long enough to discuss that. So let’s stick with what you can and should be doing and what will be necessary for an audit.

 

1. Know your water quality

 You will have to test your own facility water to ensure that at the point of use it complies with the standards for potable water given below. Don’t assume because you are drawing from a municipal source everything is under control. This heavy rains can cause contamination.

 

2. Sampling plan & sampling points

You want to ensure your internal system is not contaminating the incoming water so you should have a plan in place and test at various internal points to ensure this.

 

3. Check your water storage tanks too

If you are using water storage tanks these should also be monitored, to ensure that they are not a source of contamination.

 

4. Internal water treatment systems 

Make sure to maintain your internal water treatment systems. If you are adding chlorine then ensure you have a system for measuring residual chlorine levels and the microbiological quality of the water. Alternative disinfectant systems are available – make an informed decision.

 

5. Keep records of your testing

You will need to show a positive trend and you will need sufficient records to demonstrate this. In other words – one sample will not cut it. (You have heard of beginners luck?)

 

SANS 241 Requirements

 

Microbiological determinands 

E. coli

(mpn per 100 mL)

Acute health

0

Total Coliforms

(mpn per 100 mL)

Operational

10

Heterotrophic Plate Count

(cfu per 1 mL)

Operational

 ≤1000

Cryptosporidium spp

(org / 10 Litre)

Acute health

0

Giardia spp

(org / 10 Litre)

Acute health

0

Somatic Coliphages

(count per 10 mL)

Operational

0

 

 

 

 

Physical and Aesthetic determinands

Colour

(mg / L as Pt-Co)

Aesthetic

≤15

Conductivity

(mS / m)

Aesthetic

≤170

Total Dissolved Solids

(mg / L)

Aesthetic

≤1200

Turbidity

(NTU)

Operational

≤1

Turbidity

(NTU)

Aesthetic

≤5

pH

(pH units)

Operational

≥ 5 to ≤ 9.7

Chemical Properties Macro determinands

Ammonia

(mg / L as N)

Aesthetic

≤1.5

Chloride

(mg / L as Cl)

Aesthetic

≤300

Free chlorine

(mg / L as Cl2 )

Chronic health 

≤5

Monochloramine

(mg / L as Cl2 )

Chronic health

≤4.1

Fluoride

(mg / L as F)

Chronic health

≤1.5

Nitrate

(mg / L as N)

Acute health

≤11

Nitrite

(mg / L as N)

Acute health

≤0.9

Combined nitrate plus nitrite

(NO2 /0.9 + NO3 /11)

Acute health

 ≤1

Residual disinfectant

(mg / L)

Operational

≥0.1 Sum of Free and Monochloramine

Sodium

(mg / L as Na)

Aesthetic

≤200

Sulphate

(mg / L as SO4 )

Aesthetic

≤250

Sulphate

(mg / L as SO4 )

Acute health

 ≤500

Zinc

(mg / L as Zn)

Aesthetic

≤5

Chemical Properties Micro determinands

Aluminium

(μg / L as Al)

Operational

≤300

Antimony

(μg / L as Sb)

Chronic health

≤20

Arsenic

(μg / L as As)

Chronic health

≤10

Barium

(μg / L as Ba)

Chronic health

≤700

Boron

(μg / L as B)

Chronic health

≤2400

Cadmium

(μg / L as Cd)

Chronic health

≤3

Chromium (Total)

(μg / L as Cr)

Chronic health

≤50

Copper

(μg / L as Cu)

Chronic health

≤2000

Cyanide (Recoverable)

(μg / L as CN)

Acute health

≤200

Iron

(μg / L as Fe)

Chronic health

≤2000

Iron

(μg / L as Fe)

Aesthetic

≤300

Lead

(μg / L as Pb)

Chronic health

≤10

Manganese

(μg / L as Mn)

Chronic health

≤400

Manganese

(μg / L as Mn)

Aesthetic

≤100

Mercury

(μg / L as Hg)

Chronic health

≤6

Nickel

μg / L as Ni)

Chronic health

≤70

Selenium

(μg / L as Se)

Chronic health

≤40

Uranium

(μg / L as U)

Chronic health

≤30

Organic determinands

Total Organic Carbon

(mg / L)

Chronic health

≤10

Phenols as C6H5OH

(μg / L)

Aesthetic

≤10

Chloroform - CHCl3

(μg / L)

Chronic health

 ≤300

Bromoform - CHBr3

(μg / L

Chronic health

≤100

Dibromochloromethane - CHBr2Cl

(μg / L)

Chronic health

≤100

Bromodichloromethane - CHBrCl2

(μg / L)

Chronic health

≤60

Combined trihalomethanes

(CHCl3 /300 + CHBr3 /100 + CHBr2Cl/100 + CHBrCl2 /60)

Chronic health

≤1

Total Microcystin (5)

(μg / L)

Chronic health

≤1

 

Sources:  http://www.reservoir.co.za/municipalities/tshwane/Tshwane_Aug2016.pdf