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What you should know about the new 2015 Blue Drop Limits (SANS 241:2015 Drinking Water)

Written by Janice M on . Posted in Water & Environmental

The new SANS 241:2015 Drinking Water Standards were published in March 2015. Blue Drop limits will be based on this.

The Drinking Water Standards list the determinands and corresponding limits that need to be measured in order to determine that the quality of drinking water is safe for us to drink.

You can purchase the SANS 241-1 and SANS 241-2 :2015 Standards here at the SABS webstore

What has changed since SANS 241:2006 and SANS 241:2011?

  • Some determinands have become more lenient (such as cyanide and selenium) and others are more stringent (such as lead). These changes are based on new research and changes in the WHO Guidelines for Drinking Water Quality
  • There are 18 new determinands (such as barium and boron) and 9 determinands have been removed
  • Under Microbiological determinands, there is increased focus on two protozoan parasites, Cryptosporidium and Giardia species
  • Also, compliance with SANS 241 Microbiological Determinands is highly rated in a Drinking Water quality system by DWA. Chemical determinands have a secondary high rating. The remaining three determinands are: Physical, aesthetic and operational

Table of 2015 Blue Drop Limits (derived from SANS 241)

Determinand Unit

Department of Water Affairs

WHO limits
might equate to
SANS 241: 2013 limits
↑relaxed limit, ↓more stringent limit


(derived from SANS 241:2014)

SANS 241: 2011

WHO 4th ed Guidelines  
Risk Standard limits Risk Guidelines Risk Standard limits  



Escherichia coli (E.coli)

count/100ml Acute Health Not Detected (ND)     Acute Health Not Detected (ND)


Faecal coliforms
count/100ml Acute Health ND     Acute Health ND
Cryptosporidium species
count/10ml         Acute Health ND  

Giardia species

count/10ml         Acute Health ND  
Total coliforms count/100ml Operational < 10     Operational < 10  
Heterotrophic plate count count/1ml         Operational < 1 000


Free Chlorine mg/l Chronic Health ≤ 5 (new) Chronic Health ≤ 5  
Monochloramine mg/l Chronic Health ≤ 3 (new) Chronic Health ≤ 3  
Colour Pt-Co     Aesthetic < 15
Conductivity at 25°C mS/m Aesthetic ≤ 170     Aesthetic ≤ 170
Total Dissolved Solids mg/l Aesthetic ≤ 1 200     Aesthetic ≤ 1 200
Turbidity NTU Operational ≤ 1     Operational
≤ 1
≤ 5

pH at 25°C pH units Operational ≤ 5 to ≤ 9.7     Operational ≤ 5 to ≤ 9.7



Ammonia as N mg/l Aesthetic ≤1.5     Aesthetic ≤ 1.5
Chloride as Cl mg/l Aesthetic ≤ 300     Aesthetic ≤300
Fluoride as F mg/l Chronic Health ≤ 1.5 Chronic Health ≤ 1.5 ↑ Chronic Health ≤ 1.5
Magnesium as Mg            
Nitrate as N mg/l Acute Health ≤ 11 Acute Health ≤ 11 (new) Acute Health ≤ 11  
Nitrite as N mg/l Acute Health ≤ 0.9 Acute Health ≤ 0.9 (new) Acute Health ≤ 0.9  
Nitrite-nitrate ratio           Acute Health ≤ 1  
Nitrate and Nitrite as N mg/l      
Sodium as Na mg/l Aesthetic ≤ 200     Aesthetic ≤ 200
Sulfate as SO42- mg/l Acute Health ≤ 500 Acute Health ≤ 500↑ Acute Health
≤ 500
≤ 250

Zinc as Zn mg/l Aesthetic ≤ 5     Aesthetic ≤ 5
Aluminium as Al µg/l Operational ≤ 300     Operational ≤ 300
Antimony as Sb µg/l Chronic Health ≤ 20 Chronic Health ≤ 20 ↑ Chronic Health ≤ 20
Arsenic as As µg/l Chronic Health ≤ 10 Chronic Health ≤ 10
Barium as Ba µg/l     Chronic Health ≤ 700  
Boron as B µg/l     Chronic Health ≤ 2 400  
Cadmium as Cd µg/l Chronic Health ≤ 3 ↓ Chronic Health ≤ 3
Chromium (total) as Cr µg/l Chronic Health ≤ 50 ↓ Chronic Health ≤ 50
Cobalt as Co µg/l      
Copper as Cu µg/l Chronic Health ≤ 2000 Chronic Health ≤ 2 000 ↑ Chronic Health ≤ 2 000
Cyanide (recoverable) as CN µg/l Acute Health ≤ 70 Acute Health ≤ 70 ↑ Acute Health ≤ 200
Iron as Fe µg/l Aesthetic ≤ 300 Chronic Health ≤ 2000
Chronic Health

≤ 2 000
≤ 300
Lead as Pb µg/l Chronic Health ≤ 10 ↓ Chronic Health ≤ 10
Manganese as Mn µg/l Chronic Health ≤ 500
Chronic Health

≤ 400
≤ 100
Mercury as Hg µg/l Chronic Health ≤ 6 Chronic Health ≤ 6 ↑ Chronic Health ≤ 6
Nickel as Ni µg/l Chronic Health ≤ 70 ↓ Chronic Health ≤ 70
Selenium as Se µg/l Chronic Health ≤ 10 ↓ Chronic Health ≤ 40
Uranium as U µg/l Chronic Health ≤ 15 (new) Chronic Health ≤ 30  
Vanadium as V µg/l      


Dissolved organic carbon as C mg/l      
Total organic carbon as C mg/l Chronic Health ≤ 10 Chronic Health ≤ 10 (new) Chronic Health ≤ 10
Trihalomethanes (total) mg/l      


µg/l Chronic Health ≤ 300 Chronic Health 300 Chronic Health ≤ 300  
µg/l Chronic Health ≤ 100 Chronic Health 100 Chronic Health ≤ 100  
µg/l Chronic Health ≤ 100 Chronic Health 100 Chronic Health ≤ 100  
µg/l Chronic Health ≤ 60 Chronic Health 60 Chronic Health ≤ 60  
Trihalomethane ratio           Chronic Health ≤ 1  
Total Microcystin as LR µg/l Chronic Health 1 (new) Chronic Health ≤ 1  
Phenols µg/l Aesthetic ≤ 10     Aesthetic ≤ 10
Free Chlorine:                
Treatment works
mg/l         Operational > 0 to ≤ 0.5  
Points of consumption
mg/l         Operational > 0 to ≤ 0.2  
Treatment works
mg/l         Operational > 0 to ≤ 0.5  
Points of consumption
mg/l         Operational > 0 to ≤ 0.2  

*Source: Department of Water Affairs, 2015 Blue Drop Limits

Download the print version at the DWA website

Instruments used to measure the Determinands of Water Quality:

Historical comments (17)

  • Scout Hoodies


    Hi! Would you mind if I share your blog with my twitter group?
    There’s a lot of people that I think would really appreciate your content.

    Please let me know. Thanks

    • Janice M


      Hi, you are welcome to share this blog content, kindly include a link to our site.

  • |

    Keep this ցoing please, great job!

  • Neville


    Just received our pH level of 8.31 is that ok?

    • Janice M


      Hi Neville. According to the table, the standard limits state that the pH levels can be between 5 and 9.7 at 25 degrees C. A reading of 8.31 is suitable.

  • SnowGem Pool


    “I am just starting to learn about all of this. Thanks for your help!”

  • Moses


    Hi, what is the different of using handheld and benchtop photometer? i believe that handheld meters are fast, can I store those results to the BDS for example?

    • Janice M


      Hi Moses
      There is a difference in size and portability – the larger benchtop style is easier to use in a laboratory situation and the handheld photometer is smaller and easier to use in the field. Both are electronic and show results quickly. Benchtop photometers have data storage facilities; some handheld photometers have data storage facilities, depending on what make and model you select.

  • Moses


    Hi Janice

    Water use authorities are required to record water quality data on the Blue Drop System. My question is what is the differences between the results obtained from accredited lab and results obtained from using portable meter? Can I store results obtained using portable meter on the Blue Drop System for an example?

    • Janice M


      The difference is that accredited laboratories are using photometers that analyse parameters according to internationally approved test methods.
      Whether the portable meter can give similar or the same results depends on the make and model of photometer being used, as not all photometers
      are manufactured according to high standards. If the make and model is supplied, we can advise if the portable photometer will read in very close
      proximity to the photometers used by accredited laboratories.

      Please contact sales@selectech.co.za for more comprehensive assistance.

  • jacqueline


    I have a question.
    In a Atmospheric water generator system with ultra filtration and UV is a TMA of >10 000cfu/ml at all a danger for health…
    This system has a open unsealed reservoir….and I don’t think the filters are sufficient if the TMA is so much?

  • Reina


    Outstanding post however , I was wanting to know if you could write
    a litte more on this subject? I’d be very thankful if you
    could elaborate a little bit more. Bless you!

    • Janice M


      Hi, what aspect of drinking water limits are you interested in?

  • Lionel



    When should a water shop like OASIS send water monsters away to be tested and should they have a SANS 241 certificate (or any other certificate) to sell bottled water to the public?


    • Janice M


      Charlotte Metcalf, CEO of SANBWA responds:
      There are two main issues pertaining to this question i.e. re-fill vs bottled water:

      1. Companies that re-fill water calling it “bottled water” is incorrect and causes confusion in the mind of the consumer by comparing their re-filled product with bottled water.
      Water that is treated and then filled into the consumer’s container falls under “drinking water” and is legislated by Dept Water Affairs and tested according to SANS 241.
      I am not sure if SANS 241 stipulates the frequency for testing. If I was the consumer, I would like to think that they test the water for chemical parameters regularly to ensure that their processing such as RO is effective. Microbiological parameters can vary due to the fluctuating microbial load from the municipal source and should in my mind be tested at least weekly. However the act of filling it into the consumer’s bottle will have an effect on the microbial content as these containers are not sterile.
      2. Bottled water on the other hand is legislated as a food by the Department of Health. It adheres to more stringent and per production batch testing. The source is tested and registered. The facility and production is subject to hygiene and design legislation.
      3. When and if a company bottles both re-fill and bottled water it is possible that the bottled water (hermetically sealed in new container) is not treated and tested according to bottled water specific legislation (R718, R455, R962, R692, R146 etc.). These products should be branded differently and produced and tested according to the different pieces of legislation.
      4. People should not confuse re-fill and bottled water.

      Hope this helps

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