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All About Sewage

Sewage Treatment Systems


All sewage treatment systems are biological. We ask Mother Nature to take out the stuff we put in, and she had done that since time, and the
best large scale sewage systems are -

Maturation Ponds !

Yes, maturation ponds.  These are large open dams, where foul water will enter the first of several dam like structures, trickles through to the next, and then the next.  The water exits, absolutely clean, pollution free and absent of any pathogens. The ponds are quite specific in dimensions, and are generally lined with waterproofing material, to stop groundwater seepage.

Maturation ponds are quite specific in their design, and based on the maximum daily water volume. This ensures a natural division of the three main biological processes for wastewater treatment - anaerobic, anoxic, and aerobic, which will remove all the nutrients, and, the water could be clarified. The depth and surface area are most important as water's upper surface would naturally absorb oxygen from the air, thus becoming the aerated section. As the depth increases, the natural oxygen absorption decreases, thereby creating a anoxic zones, and finally at the bottom, you will find no oxygen. The bottom will develop some sludge, which would need to be removed periodically.  And, you might ask, what happens to the pathogens - the bugs normally found in treated sewage? Well, they all die, either eaten by other bugs, or die naturally as they exceeded their lifespan (i.e. died of old age). There are exceptions, but generally this water can go back in the river, or water course. 

sewage treatment systemsMaturation ponds can treat (screened) sewage without electricity, or disinfectants.  Furthermore, the water will attract a vast array of wildlife, particularly birds, and small reptiles. (Image - Bela Bela Nov2021)

So, why don't we have these instead of the formal Wastewater Treatment Works, or sewage treatment package plants? Space - maturation ponds need lots of space, and it must be relatively flat.  This space is often reserved for housing developments, shopping malls, farming or roads. And, maturation ponds can emit 'rotten egg' odours, called septicity, caused by hydrogen sulphide. Ponds are not nice for us, but great for everything else.

Septic Tanks and French drains

This is the most common of all sewage disposal systems, particularly in residential and rural areas, and generally there was no negative environmental impact, in the past. A farm of 10 000 hectares, with one dwelling on it, would have little chance of untreated sewage reaching the environment. The same farm has now been developed into a township / estate / village with 100 000 people, (each person generating up to 250 litres per day) living there, will no longer enjoy the same clean environment. Sewage will now need to be cleaned up, and the water released back to nature.

Wastewater Treatment Works (WWTW)

This type of sewage treatment is Activated Sludge, and is the best method of treating large volumes of wastewater.  There are various types / designs of activated sludge, but most are based on the same technology. The sludge (solid particles) is active with bacteria, and the bacteria live there. Package plants - generally - are quite different (see Package Plants below).

Bela Bela WWTWLarge Wastewater Treatment system suitable for large volumes - Bela Bela Municipal wastewater facility (Image Nov 2021)

When towns and cities develop, waterbourne sewerage systems are built which includes pipes (from homes, offices and factories), pump stations, rising mains, and the water treatment facilities - Wastewater Treatment Works. Normally the WWTW is at the lowest point in the area, and by their nature, often close to catchment areas - rivers and streams (even dams).

These WWTW are mostly civil works (concrete and the clay) and would include pumps / pumpstations, de-gritters, solids screening, bio-digestors, bioflilters, aeration tanks, clarifiers, settlement tanks and some form of disinfection. These treatment facilities need constant attention, by skilled and fully trained technicians. Water and sludge is constantly monitored, often with on-site laboratory analysis. Sludge age and density, pH, temperature and a wide range of other variables are checked on a daily basis. Lots can go wrong, particularly since this type of facility gets abused with harsh chemicals, excessive solids, factory effluent, and rainwater.

With the normal education and training, these works operated well, and rarely failed outright. Since the DoD (Dawn of Democracy) maintenance and training have been forgotten, and funds much needed to keep things working were spent on more important items, like mayor's cars and staffing for cadres.

Making matters worse, is that townships are being developed at a surprising rate, and due to the close proximity of dwellings to each other (and the high occupancy rate), waterbourne sewerage systems are imperitive. This just adds to an overburden of an already failed facility. For many, there is no escape from pollution, with sickness and death flowing in and out of towns and cities.

Package Plants

Enter the on-site sewage treatment system - Package Plants - the item which treats your sewage, producing clear and compliant reusable (not potable) water for a variety of other water thirsty uses.

Generally, these systems are not activated sludge designs, particularly the smaller duties, like the single house unit. The few designs that are based on activated sludge technology, wont be near any homes, since they are "open sewers" and may have offensive odours, and, could attract flies. Furthermore, all activated sludge systems will need sludge drying beds.
Drying BedsSludge drying beds - essential for activated sludge systems - Bela Bela municipal WWTW (Image Nov 2021)

Drying beds can be problematic. Sludge has to be just the right age, and density, to be released into the open drying beds. Failing which, the sludge can produce some really awful odours, and often attract flies. Furthermore, releasing sludge just prior to rain, may result in the drying bed becoming a dam. The above image shows drying beds almost unused, due to DoD (see above).

Sewage treatment systems, like the Scarab, do not use  activated sludge technology. Raw sewage is retained in predigestion chambers (similar to septic tanks), and only the foul water goes into the package plant. Since there is very little sludge, bacteria are offered plastic media instead, which they find quite accommodating. Since this wastewater is much 'cleaner' the whole process is cleaner, and water quality is that much better, generally.

Do package plants smell?
Some do. The systems that have parts of the process missing, or when something has failed, will smell. In some cases, the entire process is flawed, but the developers / marketers ignore this fact, and still produce these products for the public, that knowingly don't work. The Sewage Package Plant Association of South Africa (SEWPACKSA) should have solved this problem, but didn't.  Some of those flawed products were marketed by the same people that were running the association. Fortunately, SEWPACKSA no longer functions, and the idea of the industry being self regulating is now in effect. 

Septic tanks and their ugly sisters, soakaways are generally being rejected these days. The only option for sewage disposal is a package plant, and whilst these items can be  expensive, there is hope that once full implimentation is reached, prices might drop. However, until such time as there is a standard, particularly in performance, having a system installed on your property may not offer you any peace of mind.  


Treat your water to a Scarab® system.



The Package Plant People

SCARAB® was owned by Steve Nicol and the late Gordon Nicol, and their experience in the sewer industry started as early as 1982. In 1986, Steve started his own business, United Pumping, and Gordon joined him in 1988. Primarily, United Pumping, now Unipump cc, serviced and maintained sewer pumping and treatment equipment for the public and private sectors. With this experience, the family team were asked by business associates, to help develop a new sewage package plant and that product became commercialized in 1997. The association ended in 2001 and SCARAB® was launched. 

SCARAB® is a listed Top 100 South African company (tt100) for it's technology in 2004, 2005 and 2006.  The 2006 tt100 Bio2Biz award in Durban, was presented to Steve Nicol, by the Science and Technology deputy minister, Derek Hanekom. Since 2006, Scarab has been recognised by a wide range of local and international experts, for for company's efforts to produce the very best products, in an industry that will need to perform, if it is to save the earth's most precious resource - WATER. (see accolades here)

In 2011, the company relocated to Limpopo, which was not only closer to it's local and international markets, based in Johannesburg, but gave the team opportunity to thrive, in a relaxed rural environment.

SCARAB® Australia (Pty) Ltd ( link here, ) was launched in May 2013, and we have 3 successful package plants in Queensland.

Treat your water to a Scarab® system.

Scarab® Water Office

Best Domestic Sewage Treatment Systems in Africa

The Scarab® Team

The Package Plant People.
Sewage Treatment systems - The Water Wizards

Steve Nicol - Scarab SA

Contact Details

Scarab Water (South Africa)

                         
Stefan Joubert  -  Sales

Mobile -  082 307 9470
Email - stefan@scarabsa.co.za
Web - www.scarabsa.co.za

Steve Nicol - Director / Founder

Mobile -  082 441 9549
Email - steve@scarabsa.co.za
Web - www.scarabsa.co.za

Scarab in Australia 

 Year 2021 Scarab dung beetle