Water Quality in Oudtshoorn

Oudtshoorn, 02 December 2019 – Following the recent rains, Oudtshoorn is currently experiencing a deterioration in water quality with regard to turbidity, which is the measurement of colloidal suspended solids in water (i.e. an indication of particles suspended in the water).

The high intensity rainstorm (75mm in less than two days) in the catchment area of the Raubenheimer Dam caused flash floods resulting in muddy water entering the dam. According to national standards, the aim is to keep turbidity below 1 NTu (NTu being the measurement unit for turbidity). Under normal conditions the turbidity of the water from the dam ranges between 0.5 and 3 NTu, which is still acceptable. Directly after the recent rains, the turbidity increased to above 40 NTu, but has since decreased to 30 NTu. It can thus be seen that the quality is improving and should return to normal within a few weeks.

The increase in turbidity (i.e. the presence if small particles in the water) are generally not regarded as harmful. It can however compromise the effectiveness of the disinfection. The quality of the water is monitored on a regular basis and tests done after the recent rain still indicate no presence of E.Coli (an indication of possible harmful bacteria being present). It is however recommended that water for drinking purposes be boiled until the water quality is back to normal.

The only water treatment taking place at the Raubenheimer Dam is disinfection by means of chlorination. No water treatment plant exists and the thus no filtration of the water is done. This has been the situation since the dam was built in the early 1970’s. Due to the exceptionally high quality of raw water this has been deemed acceptable for most of the time. However, following heavy rainfall, the water quality does deteriorate and the situation can continue for a few weeks.

To address this periodic deterioration of the water quality, a treatment works is needed. This  option has been investigated numerous times by the Municipality with the latest report compiled in 2014, recommending a filtration plant to the value of approximately R100 million to be constructed.  This is now again under investigation and funding possibilities are being pursued.


Waterkwaliteit in Oudtshoorn

Oudtshoorn, 02 Desember 2019 – Na afloop van die onlangse reën, ervaar Oudtshoorn tans dat die drinkwater troebel is. Die hoë intensiteit van die onlangse reën (75mm in minder as twee dae) het tot gevolg gehad dat modderige water die dam ingevloei het en die water vertroebel het. Volgens Nasionale Standaarde word aanbeveel dat troebelheid onder 1NTu behoort te wees (NTu is die eenheid waarin troebelheid gemeet word). 

Onder normale omstandighede wissel die troebelheid van Oudtshoorn se water tussen 0.5 tot 3 NTu, wat as aanvaarbaar beskou word. Direk na die onlangse reën het die troebelheid egter gestyg tot 40 NTu en het intussen gedaal na 30 NTu. Die troebelheid is dus besig om af te neem en behoort binne ‘n paar weke weer na normaal terug te keer.

Die toename in troebelheid hou geen direkte gevaar in nie, maar kan wel die effektiwiteit van die chlorinering beinvloed. Die kwaliteit van die water word op gereelde basis getoets en toetse net die reën het bevestig dat daar geen tekens van E.Coli in die water is nie (E.Coli is ‘n aanduiding dat daar moontlike skadelike bakterieë in die water mag wees). Ons beveel egter aan om drinkwater te kook tot tyd en wyl die water kwaliteit na normaal terugkeer.

Geen waterwerke bestaan by die Raubenheimerdam vir die suiwering van drinkwater nie en die enigste behadeling wat tans gedoen word is die ontsmetting van die water deurmiddel van chlorinering met chloorgas. Dit is die situasie sedert die bou van die dam in die vroeë 1970’s. As gevolg van die besonderse hoë kwaliteit van die rou water word dit aanvaarvaar gevind vir die meeste van die tyd. Na afloop van hoë intensiteit reën storms vertroebel die water egter somtyds en kan troebel water vir ‘n paar weke ervaar word.

Die enigste manier om die troebelheid uit die water te haal is deur middel van filtrasie. Die moontlikheid om ‘n suiweringswerke te bou is al verskeie kere deur die Munisipaliteit ondersoek met die laaste ondersoek  in 2014 gedoen. Die ondersoek se bevinding was dat ‘n suiweringswerke met ‘n koste van ongeveer R100 miljoen benodig word. Hierdie opsie word tans weer ondersoek en moontlike befondsings word nagevolg.

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