Source of Water

groundwater (shallow), 1,000-2,000 mg/l,

brackish groundwater, 2,000-8,000 mg/l, 

seawater, 45,000 mall, 

product water from MSF (multi-stage flash) desalination, 25-50 mg/l, 

reclaimed treated waste water, 2,500 mg/l. Well water

Field	Aquifer	No. of wells	Yield(million m³/year)		Salinity (TDS, mg/l)
			Existing	Potential
Rawdatain and Um al-Aish	Dibdibba F	52	2.5	6.6	700-1,200
Shigaya A, B. C	Kuwait G	60	53	66	3,000-4,000
Shigaya D, E	DammanF	54	-	42	3,000-4,500
Sulaibiya	Damman F	133	25-33	33	4,500-5,500
Abduliya	Damman F	14	8	-	4,500
Wafra	Kuwait G	(110)	33-42	50	4,000-6,000
Abdali-Um Nigga	Dibdibba F	(110)	20-25	33-42	3,000-7,000
Source: Kuwait Institute for Scientific Research, in 1990.

Municipal Tap Water

Kuwait is one of the world's leaders in the production of fresh water from the sea. Large Multi Stage Flash (MSF) distillation plants are often paired with power plants in a Co-generation configuration. Waste heat from the power plant is used to heat the seawater, providing cooling for the power plant at the same time. Kuwait developed Co-generation stations, in the early 1950s and have been in use since then. The annual production of fresh (distilled) water is estimated to be now 366 million m³.

Installed capacity of co-generation stations in Kuwait

	Fresh water production		Power generation (MW)	Date
	Million m³/year Mig/day
Shuwaikh	53	32	324	1960-70
Shuaiba North	21	14	400	1965-71
Shuaiba South	50	30	804	1971-75
Doha East	71	43	1,158	1978-79
Doha West	159	96	2,400	1985
Az-Zour South
stage I	10	06
stage II	119	72	2,511	1991
Total	366	221	5,769
Source: Kuwait Institute for Scientific Research, in 1990.

Schematic of a Co-generation desalination plant


A variety of chemicals being introduced during thermal desalination process. Mostly these are intended for the safeguarding of plant machinery and pipe lines. Table below profiles chemicals which are most frequently used in seawater thermal desalination.

Dose rates are only indicative and are shown as mg/litre of chemical in the relevant process stream (MU=Make Up Water, CW=Cooling Water).

Table 2.1 Chemicals used in thermal desalination processes

Chemical Type	Purpose of Use	Dose And Feed Location	Application
Scale inhibitor (Usually phosphonates, polyphosphate, polymaleic or polycarboxylic acids, or a blend of several of these)	Usually crystal modifiers that avoid precipitation and development of deposits (primarily CaCO3, Mg (OH)2. Blends may include dispersant properties to prevent crystals adhering to equipment.	1-8 mg/litre, MU	Used in all thermal desalination processes.
Acid (usually sulphuric acid),	An alternative scale inhibitor. By lowering pH calcium carbonate and magnesium hydroxide scale formation is avoided.	≈100 mg/litre, MU	Used only in MSF desalination.
Antifoam (Poly Othelyne Ethylene Oxide or similar surfactant)	Uncorrected foaming due to unusual feed water conditions may overwhelm the process indicated by high product TDS (carryover).	≈0.1 mg/litre, MU	Used intermittently in all thermal processes but primarily MSF.
Oxidizing Agent: most	To control bio-fouling and	≈1.0 mg/litre,	Used for large surface and sea
often a form of chlorine,	aquatic organism growth in	CW	water intakes.
however biocides may	the intake and desalination
have some use, particularly	equipment. Continuous
for smaller systems.	dosing of 0.5-2 mg/L active Cl2 with intermittent shock dosing (site specific but may be 3.7 mg/L for 30-120 minutes every 1-5 days).
Sodium bisulfite.	Oxygen scavenger to remove traces of residual oxygen or chlorine in the brine recirculation.	≈0.5 mg/litre, MU	Used only in MSF desalination systems and in intermittent mode.

Chlorination

Chlorine, the most common disinfectant, is effective in killing most pathogenic bacteria and viruses. The output water from desalination plants is chlorinated at local distribution centres to provide a residual concentration of 0.5 to 2.0 ppm. Chlorine is not effective in killing certain protozoans like cryptosporidium, however.

One complication that arises with chlorination is the formation of by-products during the disinfection process. Chlorination by-products are chemicals that result from the reaction of chlorine with organic substances in water. Table below lists some common chlorination by-products.

Chloroform	Range 0.7 - 540 µg/L, Mean 26.4 µg/L
Bromodichloromethane	Range 1.9 - 183 µg/L, Mean 9.1 µg/L
Chlorodibromomethane	Range 0.4 - 280 µg/L, Mean 5.7 µg/L
Bromoform	Range 0.4 - 280 µg/L, Mean 5.7 µg/L
Chloroacetic Acid	Range <1 - 5 µg/L
Dichloroacetic Acid	Range 12 - 79 µg/L, Mean 47 µg/L
Trichloroacetic Acid	Range 4 - 103 µg/L, Mean 38 µg/L
Dichloroacetonitrile	Range 1.9 - 24 µg/L, Mean 2 µg/L

Disinfection by-products have been linked to adverse health effects, including cancer, in laboratory animals. Table 2 summarizes the health effects of some chlorination by-products.

Long-term risks of consuming chlorinated water include excessive free radical formation, which accelerates aging, increases vulnerability to genetic mutation and cancer development, hinders cholesterol metabolism, and promotes hardening of arteries. Effect of boiling municipal water:

The recommend time bringing water to a boil for necessary disinfection, varies from 1-25 minutes. Boiling tap water for such prolonged period simply contributes to increased TDS. In reality, due to chlorination, the water is already disinfected. Boiling does not help to eliminate chlorination by-products or chemicals introduced during desalination process.