GES Leads Desalination and Well Improvement Projects for the Urban Sector
Water treatment by well improvement and desalination is gaining a central place in water management in cities and rural towns. In recent years GES – Global Environmental Solutions, which specializes in water and waste-water treatment for the industrial and institutional sector, has won tenders issued by regional municipalities for the establishment and operation of desalination and well-water improvement facilities, by using state of the art technologies.
The increase in the population of the Middle East and the lack of a political solution to the regional conflict turn the water problem into a central issue with political implications.
Water consumption in Israel, according to the Ministry of Environmental Protection, is approximately 2,120 million m3 per annum, of which approximately 1,500 m3 per annum is fresh water, approximately 450 million m3 per annum is reclaimed water, and approximately 170 m3 per annum is flood water and brackish water.
The main consumer of water is the agricultural sector, which accounts for about 60% of the total consumption, followed by urban and residential consumption, which accounts for an additional 30% of the total consumption. The remaining 10% is provided for industry.
Future forecasts expect an increase in water consumption in Israel, especially in residential consumption, as a result of the continuous rise in living standards and population growth.
The forecast for water consumption in 2015 is estimated at approximately 2,500 million m3 per annum.
The Water Problem in Israel – Quantity and Quality
Over-drawing of water impacts water quality. For example, the coastal aquifer, which in past years was characterized by low salinity, because of over-drawing, the water quality has begun to deteriorate. The current assessment is that in approximately 20 years, nearly half of the water drawn from the coastal aquifer will contain salts at a level greater than that recommended for drinking water.
The main parameters measured and followed are: nitrates, salts (usually chlorides), and microorganisms. Nitrates are a result of the oxidation of organic nitrogen and ammonia, which are both found in high concentrations in sewage and fertilizers. A high nitrate concentration can impede the bonding of oxygen in babies' blood which could lead to death. This is also recognized as a carcinogenic agent.
The accepted standard for nitrates in the United States and Europe is no more than 45 mg/l. In Israel, about 60% of water drawn from the coastal aquifer contains nitrates in concentrations greater than 45 mg/l. Therefore, the standard was initially set at 90 mg/l.
In 1994, the standard was lowered to 70 mg/l, and it is safe to assume that the standard will continue to be made stricter in the future. Today, it should be emphasized, more than 80 wells have been closed due to nitrate contamination.
Using various different technologies, it is possible to treat the water and lower the nitrate levels to the acceptable standard. This can be done at a reasonable cost which is usually lower than the cost of producing fresh water.
Generation of Alternative Sources through Improvement of Contaminated Sources and Desalination
In light of the severity of the problem, policy makers are promoting activities for the generation of alternative sources for supplying water at the required quantity and quality, including the use of reclaimed water for agriculture. Following the Inbar Committee, a demand was made for their upgrade to a higher quality, through tertiary treatment including filtration and disinfection or expanding the use of membranes in purification facilities (MBR technologies). Use of reclaimed water is limited to the agricultural and industrial sectors, and the implications of reclaimed water for the quality of groundwater have yet to be fully understood.
GES, which specializes in the treatment of water and waste-water, is a central player in desalination and improvement projects in Israel. These projects include: a seawater desalination facility in Palmachim, a large number of brackish water desalination facilities such as the desalination facility in Atlit, Ktziot, Ma'ayan Zvi, and more.
GES has also been awarded a number of tenders for the improvement of contaminated wells in municipalities such as Tel Aviv, Bat Yam, and more. The GES motto is correct and timely preparation in order to ensure the supply of water at the required quantity and good quality.
Desalination Facility – Palmachim
The Palmachim desalination facility is a VIA MARIS project for the supply of 30 million cubic meters of desalinated water a year, for a period of 24 years. The parent companies in this project are: Granite Hacarmel, Tahal, Gaon Agro, Oceana, and Ocif.
GES, which is owned by Granite Hacarmel, performed the process design for the facility. The facility is designed to produce average daily quantities at a minimal overall cost. It is also designed with an integral ability to increase the required daily output, as per the contract, up to the client's maximal absorption ability of 102,000 m3/day. Redundancy in the facility reaches 110% during peak season, and 120% in other seasons. The quality of the product meets drinking water standards and includes special requirements for maximum concentrations of Boron, Chloride, hardness, and dissolved salt.
The main process systems in the facility are: a marine system for supplying raw seawater to the desalination facility; a pre-treatment system for treating seawater, which includes filtration and chemical-adding systems; a first pass (Pass 1) system – desalination of seawater treated in the pre-treatment systems, using RO, in six parallel devices, with three intermediate phases; a pre-treatment system for product water to remove hardness from the product water and to prevent sedimentation along the additional RO desalination membranes; a second pass (Pass 2) for optimal boron removal at a high pH environment with a recovery ratio of 98%; and hardening of the final product water for improved taste and lowered corrosiveness.
Desalination Facility – Atlit
The Atlit Desalination Facility was built by GES for the Hacarmel Coast Water Association in 2002, in order to alleviate a severe shortage of irrigation water in the Hacarmel Coast region.
Water with very low saline levels and high-quality water provided by the facility were mixed together with reclaimed water in order to allow unlimited irrigation for local farmers.
In 2004, the facility was changed in order to supply drinking water, and today supplies water to Mekorot. The facility receives raw water from four saline wells in the north-western region of the Carmel coast.
The raw water has a total salinity of 1800 mg/l, and 700 mg/l of chloride ions. The water is desalinated by reverse osmosis and the raw water undergoes pre-treatment which prepares them for desalination using reverse osmosis membranes. The process includes a deep-media filtration, adding chemicals for preventing the formation of scale on the membranes and micron filtration.
After removal of the salts by reverse osmosis, the water undergoes stabilization and adaptation to drinking water standards. Stabilization is achieved by dilution with raw water and removal of acidity by aeration. The product water has an overall salinity of less than 350 mg/l and 100 mg/l chloride ions and conform to the drinking water supply standards both in health requirements and stability, minimal hardness, and corrosiveness.
The facility operates automatically 24 hours a day and the quality of the product water is controlled continuously. The facility supplies a quantity of approximately 2 million m3/year of drinking water.
Desalination Facility – Ma'ayan Zvi
The facility is being built on agricultural land in Kibbutz Ma'ayan Zvi, and is designed to produce about 4 million m3/year of drinking water.
The raw water for the facility is to be supplied from eight saline drill sites in the area and from the southern part of the Carmel coast region. The average quality of the raw water is an overall salinity of 2500 mg/l and 1000 mg/l chloride ion.
The water is desalinated by using reverse osmosis. The raw water is to undergo pre-treatment which prepares the water for desalination using reverse osmosis membranes. The process includes a deep media filtration, addition of chemicals for the prevention of scale on the membranes, and micron filtration.
After removal of the salts through the reverse osmosis process, the water is to undergo stabilization and adaptation to drinking water standards. Stabilization is carried out using a hardening system, and acid removal is carried out by aeration.
The product water is to have an overall salinity of less than 350 mg/l and 100 mg/l of chloride ion, and will also conform to drinking water supply standards both in health requirements and stability, minimal hardness, and corrosiveness. The facility is to operate automatically 24 hours a day and product water quality is to be controlled continuously. The water is to be supplied to Mekorot.
Well Improvement Facilities – Bat Yam
GES is building for the Bat Yam Municipal Authority two well-improvement facilities. Due to contamination of the well water, drawing water from these wells was prohibited by the Ministry of Health due to unacceptable concentrations of trichloroethylene and detergents.
Use of the facility will improve the quality of the drinking water and prevent the spread of contaminants in the ground water. The facilities are to be built and operated through a 10-year BOOT agreement signed with the Bat Yam Municipal Authority.
The contaminants are to be removed by absorption using activated carbon, and the water is to be supplied to the city grid. The two wells produce water at a capacity of 150 and 175 m3/h, and all in all, a total of more than 2 million m3 treated water is to be supplied to the municipality each year. Each facility includes a system of media filters for pre-treatment, a system of activated carbon vessels, chlorination and fluorination systems, and a continuous quality control system. The water is to be supplied to the grid after quality control testing and the concentration of contaminants is to be less than 30% of the standard-permitted value.
Desalination Facility – Ktziot
The Ktziot Desalination Facility was built by GES for Mekorot in 2001, with the aim of supplying water for towns in the area both for residential consumption and for agricultural use. The facility receives raw water from two deep saline wells located at a distance of about 9 kilometers from the facility.
The overall salinity of the raw water is 5,000 mg/l, the chloride concentration is approximately 2,500 mg/l, and the water temperature is 38 degrees centigrade. In addition to the high saline level, the raw water is also characterized by a high concentration of calcium, silica, hydrogen sulfide, sulfate, boron, fluoride, barium, ammonia, and suspended solids. The raw water undergoes pre-treatment which includes removal of the hydrogen sulfide, deep substrate filtration, cooling, addition of chemicals for the prevention of sedimentation, and micron filtration. This treatment prepares the water for the desalination process, which is carried out using reverse osmosis, and with a recovery rate of 88%.
After removing the salts, the water undergoes two additional phases of treatment; boron removal and stabilization. The product water has an overall salinity of less than 350 mg/l, and conforms to the drinking water supply standards both in health requirements and stability. Today, the facility is owned by Mekorot, is operated automatically 24 hours a day and water quality is monitored continuously. Facility output: approximately 3 million m3 per year drinking water.
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