All of the piped water supplied on Grand Cayman, including Cayman Water supplied water, is desalinated seawater. Reverse osmosis separates the salt and other contaminants from the water leaving fresh water that is further treated to finished water quality and distributed to our customers.
The American Water Works Association calculates that the average per capita domestic water consumption is 69.3 US gallons per day. For a family of four, that equates to approximately 8,600 gallons per month. This does not include usage like watering the lawn, washing your car or filling a swimming pool, which can add significantly to your monthly water usage. Water wastage can increase your recorded usage by double, triple or more. For example, a “silent” running toilet leak can waste up to 7000 gallons in one month.
Any water will cause corrosion of metal. Unlike many places in the world where hard water and scaling are problems, piped water in Grand Cayman is the opposite. It is very soft water (i.e. it has fewer dissolved minerals) and as a result is more likely to draw minerals from pipes. Use plastic, brass or other corrosion resistant materials in your plumbing, especially hot water heater fittings. Replace galvanized steel fittings in your hot water plumbing to prevent leaks. Also, keeping your hot water heater temperature as low in your comfort range as you can will mitigate corrosion and prolong your water heater element life.
Cayman Water piped water contains approximately 100 milligrams of sodium per liter of water. There are various recommendations for the limit of daily sodium intake with the average around 2000 milligrams. Drinking a half a liter of tap water a day would provide approximately 2.5% of one’s recommended daily intake of sodium.
Cayman Water is a wholly owned subsidiary of Consolidated Water Company LTD. Consolidated Water is a shareholder owned company and its shares are publicly traded on the NASDAQ Stock Exchange in the United States. See the Consolidated Water Company web site for investor information
Cayman Water is the piped water utility for the Seven Mile Beach area and West Bay District of Grand Cayman. The Company was incorporated in 1973 has been providing piped water to Seven Mile Beach since then and to West Bay since 1991. Cayman Water is a wholly owned subsidiary of Consolidated Water Company LTD.
No. Cayman Water is a private enterprise business and is not part of the Cayman Islands Government. Cayman Water operates under a 20 year License Agreement granted by the Cayman Islands Government to manufacture potable water from seawater and distribute it by pipes for reward directly to end users.
Cayman Water has over 5500 service connections that serve an estimated population of about 25,000 people. In addition to residential customers, Cayman Water provides piped water service to restaurants, hotels and businesses on Seven Mile Beach and in West Bay.
Cayman Water produced 898 million US gallons of fresh water in 2017 and sold 814 million gallons to its customers in that year. The difference between the amount of water produced and the amount of water sold to customers is called non-revenue water, or water loss. This amount of water loss represents approximately 9.13% of the water produced, a rate that is very low when compared to industry standards.
Cayman Water does accommodate group tours for schools and other educational purposes. You may contact the Cayman Water offices at 945-4277 for more information on group tours.
Cayman Water reads all customer water meters once a month and bills customers each month for the water consumed. Generally, meters are read close to the end of each month, with bill processing taking approximately one week. Bills are generally mailed out by the 9th day of each month.
Go to the Rates page of this website for the current prices for Cayman Water piped water. For residential customers, piped water costs approximately 2-1/2 cents per US gallon.
Cayman Water does not set the rates it charges for water. Water rates are controlled by a formula contained in the License Agreement granted to the company by the Cayman Islands Government. Of the total base rate, 55% is adjusted annually in January based on the United States Producer Price Index, and the Cayman Islands Consumer Price Index according to a formula in the License Agreement and the remaining 45% of the base rate is not adjusted.
In addition the rate has an energy adjustment surcharge that is calculated monthly to account for volatility of energy prices. This surcharge is also calculated according to a formula in the License Agreement and is based on diesel fuel costs and electricity costs.
EAF stands for Energy Adjustment Factor. The EAF is a surcharge that is adjusted up, or down, each month according to the cost of the energy utilized by Cayman Water to produce water.
The EAF is then applied to each gallon of water consumed, in addition to the base rate. Cayman Water does not control the EAF; it is calculated according a formula contained in Cayman Water’s License Agreement and verified each month by Water Authority-Cayman.
The formula uses the average cost for energy and an efficiency constant that effectively limits the amount of the surcharge, so Cayman Water may not collect money from its customers if it does not operate its water production equipment in an energy efficient manner.
Cayman Water bills may be paid by cash, check or debit/credit cards at the Cayman Water offices located in the Regatta Office Park (formerly SafeHaven) on the West Bay Road. The cash office is located on the fourth floor of the Windward 3 building and is open from 8:30 AM to 4:30 PM, Monday through Friday. A payment drop box is also located at the cash office and payments may be dropped off anytime. The drop box should only be used for check payments.
Bills may be paid by post by check only. Please do not mail cash.
Bills may be paid at all local retail banks including Butterfield Bank, Cayman National Bank, First Caribbean, HSBC, Royal Bank of Canada, and Scotiabank.
Paying Your Bill Online – Customers can sign up for our customer portal and pay online at myaccount.caymanwater.com.
Customers can sign up for monthly Standing Orders via debit/credit cards.
Setting up a Standing Order – Currently, direct debits (Standing Orders) are not available as a payment option for Cayman Water bills.
Customers can easily verify the amount of water billed by reading their water meter themselves. See the How to read your meter page for how to do this.
All of the piped water supplied on Grand Cayman, including Cayman Water supplied water is desalinated water. That is, raw water with the same amount of salt in it as seawater is treated using a process called reverse osmosis. Reverse Osmosis separates the salt from the water leaving fresh water that is further treated to finished potable water quality and distributed to our customers.
Cayman Water piped water contains approximately 100 milligrams (mg) of sodium per liter of water. There are various recommendations for the limit of daily sodium intake, with the average being around 2000 mg. Drinking half a liter of tap water a day would provide approximately 2.5% of your recommended daily intake of sodium. For comparison, a typical cheeseburger contains almost 1500 mg of sodium, 75% of the recommended daily intake.
Cayman Water is required under the water quality regulations contained in its License Agreement, and regulated by Water Authority-Cayman, to maintain a free chlorine residual in water supplied to our customers. The amount of chlorine added must maintain an average of approximately 0.25 parts per million of free chlorine residual. This ensures that the water is disinfected and remains free of any bacteria or other organics that might be harmful to the customer. Cayman Water tests approximately 65 samples of water each month for bacteria, in order to ensure that none is present in the water.
Any water will cause corrosion of metal. Cayman Water supplied desalinated water is relatively more aggressive than naturally occurring fresh water due to its low total alkalinity, its softness (lack of mineral content) and the residual salt present. Unlike many places in the world where hard water and scaling are problems, piped water in Grand Cayman is the opposite. It is very soft water thus more corrosive. Use plastic, brass or other corrosion resistant materials in your plumbing, especially for hot water heater fittings. Do not use galvanized steel fittings in your hot water plumbing to ensure prevention of leaks. Also, keep your hot water heater temperature as low in your comfort range as you can, which will mitigate corrosion and prolong the life of your water heater element.
All chemicals added to the drinking water stream in the production and treatment process are National Sanitary Foundation (NSF) approved for potable (drinking) water use. In addition to chlorine, Cayman Water adds a food grade sodium hydroxide (caustic soda) to adjust the pH of the water to just above 7, and it adds a zinc orthophosphate corrosion inhibitor to mitigate the corrosive effects of the water.
Reverse osmosis is a filtration process that is often used for desalinating water. In order to produce fresh water from seawater, it works by using pressure to force seawater through a membrane, retaining the salt and other contaminants on one side and allowing the pure water to pass to the other side. This is the reverse of the normal osmosis process, which is the natural movement of solvent from an area of low solute concentration, through a membrane, to an area of high solute concentration when no external pressure is applied.
Given the level of development and lifestyle the people of the Cayman Islands have chosen to pursue, seawater desalination is the only viable process available to consistently and reliably supply the level of water consumption demanded by the population of Cayman Islands. Traditional fresh ground water aquifers in the western parts of Grand Cayman, in Georgetown and West Bay, have already been depleted. There is simply not enough fresh groundwater to sustain the ever increasing water demand of the Cayman Islands. While rainwater collection sustained the Cayman Islands for many generations in more modest times, it again is simply not capable of realistically providing the level of water demand today. It is estimated that to collect the amount of water produced by Cayman Water in 2011 would require a collection area of one and a half square miles, about half the area of West Bay above the West Bay cemetery.
Seawater reverse osmosis is the most energy efficient desalination technology currently available. In order to minimize the cost and amount of energy used, and the impact on the environment, reverse osmosis is the best option.
The primary difference between brackish water and seawater is in the amount of dissolved salts/solids. Seawater contains higher amounts of dissolved salts/solids (from 15,000 milligrams per liter (mg/l) to over 40,000 mg/l of total dissolved solids). Water that has only 1,000 – 15,000 mg/l dissolved salts/solids is considered to be Brackish. The greater the salt content of the water, the higher the pressure or electric power needed to treat water using membranes, resulting in higher energy costs.
Ground and surface waters have little dissolved salts or solids and with minimal treatment can yield potable water safe for drinking. Seawater has a considerable amount of dissolved salts/solids, some 70 times the amounts considered safe for human consumption. It takes a large amount of energy and highly specialized corrosion proof equipment to liberate fresh water from saline waters.
For some small island nations there is no choice but to liberate fresh water from the sea. Larger countries and coastal communities have or are considering augmenting their potable water supply with desalinated water in efforts to meet their populations growing needs and add a component of supply that is truly drought proof.
Yes, by all means please report suspected main line breaks by phoning the emergency phone number, 945-4347 or the Cayman Water offices at 945-4277.
It depends where you are located. If you live in West Bay or on Seven Mile Beach north of Watler’s Road and own your premises, then you may apply for piped water service from Cayman Water.
Water disconnection for non-payment is not considered an emergency and emergency personnel will be unable to effect reconnection of water service disconnected for non-payment. Please do not phone the emergency phone number to request reconnection of service if it has been disconnect for non-payment. Please phone the Cayman Water offices during regular business hours and speak to Customer Services to arrange payment and reconnection.
Piped water provided on Grand Cayman by Cayman Water and Water Authority-Cayman is potable water that meets World Health Organization (WHO) standards for drinking water and is perfectly safe to drink. Click here detailed Water Quality Information.
Cayman Water’s responsibility terminates at the customer meter. Your home’s plumping after the water meter is your responsibility and you should contact a plumber to assist you with problems with your home’s plumbing. If you suspect a problem at the meter box, or see water leaking from the box, then call Cayman Water.
Environmental concerns include air pollution and greenhouse gas emissions from the power plants that provide electricity and/or thermal energy to the desalination plants.
Regardless of the method used, there is always a concentrated waste product consisting of everything that was removed from the created fresh water. This is sometimes referred to as brine, often disposed of in the ocean, and careful planning and design needs to ensure that this brine stream is dispersed as quickly as possible.
Marine life entrapment and impingement of the open sea intakes and brine outfalls for these systems is an environmental concern. Design improvements and extensive monitoring of existing systems have reduced the environmental impact of both.
Obtaining fresh water from the sea is arguably more sustainable than removing water from fresh water sources such as ground water aquifers, lakes and rivers, given the relative size of the Worldâ€™s oceans compared to the dwindling size and increasingly polluted fresh water sources. Billions of gallons of fresh water are liberated daily from the oceans by the natural evaporative/precipitation water cycle.
Desalinated water is highly purified, meaning very low in dissolved salts/solids, because of this desalinated water has a high potential to dissolve solid materials, corroding pipes and other distribution fittings/equipment. Typically, desalinated water is “stabilized” by adding naturally occurring minerals, calcium and/or magnesium back into the water prior to it being put into the distribution system.
There are principally two main methods of desalting, thermal distillation and membrane separation. Due to the lower energy costs required for membrane separation methods, it is the preferred technology globally. Specifically, Reverse Osmosis membrane separation is the mostly widely used technology used for brackish and seawater desalination. Reverse osmosis is a fluid separation process in which the saline water is pressurized, and fresh water is separated from the saline by passing through a semi-permeable membrane that rejects the salts.