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Water Research Commission - Package Plants

Wastewater Package Treatment Plants – are they fit for purpose?

Compliance in the wastewater treatment industry

Our long history of compliance strategy within the wastewater treatment industry has shown some very conflicting outcomes.  The main concern has always been the regulatory town councils and, of course, the government authorities, both often being at odds with each other.

Once we had built and installed our first system, down in Drummond – KZN - on the late John Bizzel’s smallholding we have been pressured to test the product. When the plant was in, and running, Durban Metro insisted we perform 12 weekly water analysis tests – noting that there were already endorsed products, which had been pre-approved without even a sniff from head of Water and Sanitation, Neil McCleod.  

Our first attempt was thwarted by Durban Metro (DM), after we were already in our 5th week of weekly tests by Talbot & Talbot Laboratories - DM claim they had not been informed at the start. While this set us back, we were getting some really good water quality results. For weeks DM were also getting good results from their in-house laboratory.

In the meantime, Umgeni Water, offered to test our package plant, and they themselves found full compliance. Scarab achieved special standards on key indices. In comparative and simultaneous tests on two other commercial package plants, Umgeni found that those had failed hopelessly.

We felt that our Scarab system was, at that stage, the most tested design, and, that never has there been any other program for judging package plants designs, based on water quality alone.  After all, this is the sole purpose of an on-site sewage system, right? Water quality!

 

Package plants and the Water Research Commission

Then I recall Umgeni Water, the Water Research Commission (WRC) and Dept of Water and Sanitation (reference here) doing a full 6 month on-site, constant attention research program, in 2005. 3 different plant suppliers were asked to provide a trial system based on their own technologies, and the following technologies were supplied.

  • submerged biological contactor (SBC) (this is the most common of all package plants available today)
  • rotating bio contactor(RBC) (Not a popular technology and you wont find this in your garden)
  • sequencing batch reactor (SBR) (based on the activated sludge process, and not a popular technology)

The test site was a large municipal WWTW near Pietermaritzburg in Natal.

The test program ran from February until September 2005, and so included a winter period when the biological process does slow down. All designs had the same value of incoming sewage quality, and so there was no quality variation. Each of the three package plants were offered as a viable solution to domestic on-site sewage treatment, where the authorities could promote the general use, thus relieving the pressure on council owned WWTW.

Whilst there were initial teething problems on all the trial units, the RBC and the SBR performed reasonably well.  The SBC, on the other hand, did not comply once, logging 198 faults during the test period.

So, was this the end of the embarrassing product?

Not at all.  It went on for another decade before the wheels started falling off. (see below).

So, how many other products don’t perform as promised?  We were offered a design from the UK (as understood) that did not even have disinfection as a standard feature, and would never have passed the local requirements. Then, there was one of those silly little compact, electric free, underground units that offered a compliance certificate signed by the owner of the company. Both these products can now be found on South Africa shelves.

As of this year there are 42 companies selling their own brand of water recycling products in South Africa - but how many have been independently tested for compliance, prior to product launch and marketing?  And how many designs are buried, and therefore compliance cannot be easily checked? If you don't see the water quality, it cannot be verified.

 

The association of sewage treatment package plants offered like minded manufacturers a self regulatory platform, in which issues like these would be dealt with, for the benefit of both the manufacturers and the trusting public.  However, this association was considered the brainchild of the same guy whose system logged the 198 faults, and never complied once.

Scarab Package Plants - Tested and endorsed

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