ISO 9001/2008 certification
ASE has been awarded the ISO 9001/2008 certification [click to download] through KIWA International Certification. The scope of the certification covers the activities of the ASE and has been awarded for: The Design and Development of Turnkey Solutions for Water and Waste water treatment systems and Storage, Mixing and distribution of Chemical Products and PVC compound.

Through this award ASE wishes to ensure and confirms to all clients and the community of Namibia of the highest standard of service for the supply of water treatment equipment, chemicals and instruments.

Goreangab Water Reclamation Plant, Windhoek
We received the order to upgrade the existing infrastructure at the Old Goreangab water reclamation plant. It is the biggest project in ASE's history. The amount is N$ 14 000 000!

Opuwo Nanofiltration Plant

MODULAR PACKAGE TREATMENT WORKS:
NANO-FILTRATION PLANT (PRIMARILY FOR SOFTENING OF BOREHOLE WATER CONTAINING HIGH HARDNESS AND SULPHATES)

The town of Opuwo obtains its water from several boreholes on the outskirts of the town. However, the raw water is of a very poor quality and not safe to drink. Of primary health concern are high sulphate concentrations (>600 mg/l as SO₄) that render the raw water not acceptable for potable consumption. Also, the very high total hardness (>1 150 mg/l as CaCO₃) contained in the raw water, besides being a nuisance because it causes excessive scaling in pipes and other water retaining appliances, necessitates a high degree of replacement of pipes and excessive maintenance to the distribution system of the town.

ASE installed a membrane filtration plant, using Nano-Filtration (NF) technology, to treat the raw water to obtain a Class A final water. As an initial phase, Phase 1 of the project entails providing 1 000 m³/d of Class A water to Opuwo Town. Further extensions (Phases 2 and 3) to this project are planned and will be incorporated as the demand increases.

Walvis Bay Municipality
Sewage Treatment Works
Biofilter Distribution Arm Replacement
ASE was awarded the contracts for the replacement of the biofilter distribution arms at the Walvis Bay Municipal Sewage Treatment Works. The work entailed the removal of the old biofilter arms, refurbishment of the turntable base, design, manufacturing and supply of the new biofilter arms and head, as well as installation and commissioning of these.

Trickling Filter Plants
Langstrand – Henties Bay – Skorpion Zinc – Kayelekera

Sewage and effluent treatment for smaller communities and establishments is often a problem. On the one side there is an ever increasing environmental and stricter legislative pressure requiring more complicated and expensive treatment plants, while on the other hand smaller establishments want a simple, cost effective but reliable system requiring minimum operation and maintenance.

Aqua Services & Engineering (Pty) Ltd has designed a very efficient biological treatment system making use of septic tank, trickling filter and secondary settler to treat domestic sewage. The process is simple, robust, already proven in Namibia and guarantees a final effluent quality conforming to environmental standards (as presently enforceable by various legislation).

Plant Concept
The plant is based on fixed film technology. No control of the process is necessary due to the attached growth of the active microorganisms. The different treatment steps employed are as follows:

• Pre-treatment: The incoming stream is pre-treated through a hand-raked screen to remove rags, plastic bags and any large objects;
• Carbon removal: The major portion of organic pollutants are removed in a simple anaerobic reactor system, a two-chamber septic tank as already present on many farms;
• Nitrification/Polishing: Final organics removal and detoxification of the effluent is performed in the high rate trickling filter;
• Solids separation: All the pollutants that have been converted to solids (sludge) through the previous units are removed in a simple settling tank;
• Disinfection: Any remaining organisms are removed in a chlorine (or UV) disinfection stage;
• Phosphorous removal (not usually required): Phosphate can easily be removed with chemical dosing in front of the settling tank (only if required).

Biological principles

The heart of the modern trickling filter consists of a bed of highly permeable medium to which microorganisms are attached and through which wastewater is percolated.

Biological (microbial) attachment Trickling Filter Media

The organic material in the wastewater is absorbed onto the biological film. In the outer portion of the film, aerobic organisms degrade the organic material. The organisms obtain their oxygen by natural draught through the filter. As the microorganisms grow, the thickness of the slime layer increases, and the diffused oxygen is consumed before it can penetrate the full depth of the slime layer. An anaerobic environment is thus created near the surface of the media.

As the slime layer increases in thickness, the absorbed organic matter is metabolized before it can reach the microorganisms near the surface. As a result of having no external organic source available, the microorganisms near the media surface enter into an endogenous phase of growth and loose their ability to cling to the surface. The liquid then washes off the slime from the media, and new slime layer starts to grow. This phenomenon is called ‘sloughing’ and is primarily a function of the hydraulic and organic loading account for the rate of metabolism in the slime layer. The velocity in modern filters is specifically adjusted to maintain a slime layer of uniform thickness.

Advantages of the Trickling Filter System

The Trickling Filter Systems show the following advantages over other treatment technologies that produce a high quality of treated effluent:

• Simple technology. The only advanced mechanical equipment employed, are one set of submersible pumps. Also, once commissioned, no further process control is required.
• Little mechanical equipment that can break. Under the latter, only the above-mentioned pumps would be serviceable, but we always allow for two pumps, a duty and standby pump. This is done specifically keeping in mind the remote location of many of the lodges where our plants are situated.
• The final effluent produced is of a high quality and can be re-used for irrigating lawns and/or can be discharged into the environment.
• Versatility to fluctuating loads. The attached growth technology employed in trickling filters can superbly accommodate considerable fluctuations in both flow and biological loads. This is important since tourists’ numbers to many lodges show high seasonal variations. Our Trickling Filter System efficiently accommodates this.
• Minimal area required. To limit construction costs, a small footprint would be required. The trickling filter ideally satisfies this criterion.

LANGSTRAND
Langstrand ranks amongst the most popular holiday resorts in Namibia. It is situated within an environmentally sensitive and scenic coastal desert stretch visited by many tourists. This makes the resort economically one of the most important developments in Namibia.

Part of the envisaged resort developments includes an eco village and greenbelt-area. Therefore, reuse of the final effluent discharged by the sewage works is needed to save precious potable water otherwise required (and not available) to water these plants.

Being a holiday resort, extreme seasonal fluctuations in sewage volumes and loadings occur. This aspect required specific consideration during the design phase. Attention was given to the following specific points for a new sewage treatment plant for Langstrand:

• Minimizing the aesthetic impact of a sewage treatment plant on the sensitive and scenic desert environment;
• Selecting simple but most appropriate technology to deal with excessive fluctuations in sewage flows and loads in order to accommodate seasonal influxes of holiday makers;
• Introducing specific operational conditions to deal with vastly fluctuating inflows;
• Producing a final effluent for reuse that conforms to environmental legislation but still retains as much nutrient content as possible for gardening/irrigation of the envisaged greenbelt-area;
• If excess effluent is produced, this will not be discharged to sea but will be discharged to the existing reed bed area;
• Allowing for future extensions.

The above conditions led to the provision of sewage reticulation and a sewage treatment plant based on trickling filter technology. Aqua Services & Engineering (Pty) Ltd was awarded this project on the basis that they provide the complete design, supply and install the mechanical- and electrical equipment, and commission the finished plant. Other contractors appointed by the Client undertook the civil works.

HENTIES BAY

Henties Bay is a thriving holiday resort situated along the West Coast of Namibia, ca 80 km north of Swakopmund. Mainly local and South African holidaymakers frequent the town and its infrastructure is subject to huge seasonal fluctuations due to large increases in population during the holiday season.

Previously, the main method of sewage disposal to date consisted of septic tanks with soakaways, but due to the large number of residences in this town, this method of sewage disposal was unsatisfactory and could not be tolerated any more.

One of the main problems was that the ground became saturated, especially during the holiday season, and final effluent from the soakaways then seeped into the sea. Since the town was built on dunes elevated above sea level, the soakaway water also washed out dune sand thereby endangering the stability of the underground on which the houses are built. Also, the soakaway water eventually finds its way onto the beaches and also contaminates the surf, where it poses a serious health hazard and esthetically unpleasant conditions for holidaymakers along the beaches.

These unacceptable conditions necessitated urgent sewage reticulation with a proper treatment works and acceptable disposal (or reuse) of the final effluent to be provided for the town. It was therefore decided to provide sewage reticulation and a sewage treatment plant, based on trickling filter technology. The final plant will treat all sewage collected at various points throughout the town and will be constructed in three phases, of which the completion of the first phase is completed and shown above.

Aqua Services & Engineering (Pty) Ltd provided the complete design, supply and installation of the mechanical- and electrical equipment, and commissioning of the finished plant. Other contractors appointed by the client undertook the civil works.

SKORPION ZINC MINE
The Skorpion Zink mine is situated near the Rosh Pinah Town in the Karas Region in the southern part of Namibia, close to the Orange River. The mine has experienced substantial growth over the last few years resulting in the existing sewage treatment plant having run out of capacity. This necessitated an upgrade to the existing Rotating Disk filtration plant that was already installed at that stage.

The upgrade to the treatment train required was for a capacity of 150 m³/d. Various biological treatment options were considered to treat the raw sewage to a standard acceptable for discharge into the environment and/or for re-use as irrigation water for lawns. From the vast palette of advanced biological treatment technologies available, new generation trickling filter technology was considered most appropriate.

Aqua Services & Engineering (Pty) Ltd was awarded this project on the basis that they provided the complete design, supply and install the mechanical- and electrical equipment, and commissioned the finished plant. Other contractors appointed by the client undertook the civil works.

KAYELEKERA (MALAWI)

The Kayelekera Uranium Project is a new uranium mine that is being developed near the town of Karonga, in the Northern part of Malawi. The project is being managed for the Client, Paladin (Africa) Ltd, by Engineering & Projects Company (EPC).

Two sewage treatment plants were required to treat sewage generated at the mine and nearby village. Various biological treatment options were considered to treat the raw sewage to a standard acceptable for discharge into the environment and/or for re-use as irrigation water for lawns. From the vast palette of advanced biological treatment technologies available, new generation trickling filter technology was chosen because it was considered most appropriate for local conditions in Malawi, due to its simple and robust operating principles.

North Mara Gold Mine - Ongoing Project

The mining company Barrick Gold Ltd, based in Canada, is reviving their gold-mining activities at the North Mara Gold Mine in northern Tansania. Due to the rapid implementation of the works, ASE was approached to deliver a containerised sewage treatment plant with a capacity of 500 population equivalent, based on trickling filter technology. This was envisaged to be the most suitable solution for the location, as this type of plant is flexible, easily moved, as well as robust and requiring very little maintenance.

Water shortage in Walvisbay
Walvisbay has a water shortage due to flooded kuiseb river, and with my knowledge of the Kuiseb scheme, Chris decided that I should assist Namwater with the recovery of the boreholes and power lines. Since we joined them on 23 Feb 09 we recovered 5 borehole with a total capacity of 80m³/h. This bring the total suply to Walvisbay to 250m³/h.

 They are now busy repairing part of the power line and hopefully by Thursday 5 March they can start more pumps (±200m³/h) The average consumption of Walvisbay is 700m³/h.

We also installed a Sodium Hipochloride dosing station at the emergency pump station in Swakopmund that pumps water to Walvisbay.

ASE also assists with the truck to support the community with water. The truck fills up at the Fire brigade and then fill storage tanks all over town.

FLOOD RELIEF ASSISTANCE BY AQUA SERVICES & ENGINEERING

Aqua Services & Engineering , the major Namibian supplier of water and wastewater treatment plant, equipment and chemicals, allocated N$ 25,000.00 to a fund to assist stricken employees and their families with the effects of the continuing floods.

ASE conducted a survey to determine the requirements of its stricken employees and allocated N$ 8,500.00 for immediate relief to rebuild and repair housing structures. Furthermore N$ 16,500.00 has been allocated for food replenishment for the stricken families, which will be made available to the employees over the next few month to ensure the health of people, as most of their plantings have been destroyed by the floods, which would have served as their basic food source. Through this effort ASE will lighten the burden on the main relief program and ensure that dedicated relief reaches the stricken people. It is estimated that ASE will assist up to 100 people through this program.

ASE can also design, build and make available mobile potable water treatment systems, within a short period to interested parties, which can provide potable water from any available raw water source. This enables ASE to provide potable water within a short time period to the effected regions where the main potable water supply network has been destroyed or is not functional.