petak, 25. veljače 2011.
CCRES Efficiency in the Water Utility Sector
CROATIAN CENTER OF RENEWABLE ENERGY SOURCES
Efficiency in the Water Utility Sector
Water utilities provide one of the greatest bargains of modern civilization: safe, available drinking water for household and commercial use at a cost to consumers of fractions of a penny per gallon. In the United States, thousands of community water utilities operate treatment and piping systems that provide over 34 billion gallons of drinking water per day. Water utilities have historically focused on safe water quality and continuous, on-demand supply; and are heavily regulated by national governments to ensure these high levels of service. Unfortunately, a similar focus has not been given to efficiency in the water supply process, and it is believed that many water utilities suffer considerable losses from leakage and poor accounting.
With water resources increasingly stressed due to climate change and growing populations, water utilities must become water-efficient throughout the entire supply process. By employing improved methods of water auditing and loss control, water utilities have potential to reduce the large volumes of treated water that are lost to leakage, as well as to provide incentives to customers to optimize their water consumption. Water Loss Control – water efficiency practices of water suppliers – is an emerging field of practice that should be better incorporated into the drinking water utility industry in order to ensure efficiency of safe drinking water, which is the backbone of civilized society.
Who supplies my drinking water and what is their level of water efficiency?
Unlike electric power, communications, and gas service, which are mostly provided by large national companies or corporations, water is supplied in North American by over 50,000 water utilities, most of which are small municipalities, each serving less than 10,000 customers. While a few large companies exist that operate water supply systems in many states, the majority of water utilities are owned and operated by local governments, as water departments or authorities. In some areas water districts that were established to provide water for agriculture also serve residential customers. All-in-all, the water utility sector is much more fragmented than other utility sectors.
Many water customers don’t know who their water utility is, and don’t know the source (river, lake, groundwater wells) of the water that is supplied to their community. Customers can look at their water bill to identify the name of the water utility, and telephone the utility to inquire about the source of their water and their utility’s efficiency. Ask how much of the annual volume of treated water is not billed to customers due to leakage and poor accounting. Unfortunately, you’ll most likely get the answer “we don’t know.”
While all water utilities in the United States and Canada fall under strict regulatory guidelines for monitoring and ensuring adequate water quality, much less regulatory structure and rigor exists to ensure that the water supplied by water utilities is managed efficiently. In some extreme cases a water utility may only bill for 50% (or less) of the water that they treat and pump to distribution. Since few requirements exist for water utilities to audit their supplies, it is difficult to identify the total amount of water lost by water utilities. However, the United States Geologic Survey (USGS) has estimated that as much as 6 billion gallons per day (22.7 billion Liters per day) of water is lost to leakage, poor accounting and other unbilled consumption. This is more than enough water to supply the ten largest cities of the United States, and greater efforts will be needed than in the past to recoup the large volumes of lost water that will be in very great need in the future.
Older and aging infrastructure often means higher water loss. In the United States, cities on the East Coast tend to have older infrastructure and hence higher water loss than newer cities in the West. In some cases the cost to repair leaks in water mains is so high that a utility with an ample water supply may chose not to repair the leaks in an effort to keep down costs and hence water rates for the customer. In some situations with high water pressure, a main leak can cause significant damage to neaby roads and property and must be repaired as soon as possible, regardless of the cost.
Water Utility Accountability and Efficiency
Running a water utility is a complex operation. Water utilities withdraw water from a reliable source such as a river or stream, or well field. They treat the water to quality standards and pump the water into extensive underground piping systems (water distribution systems) which provide safe water directly to homes, businesses and fire hydrants. Along the way water must be tested numerous times to ensure that it is safe to drink. Ideally, water utilities should also provide metering devices at multiple locations along the supply path (the water source, treatment plant and customer endpoint) but the actual extent of metering varies from system-to-system due to inconsistent regulations and enforcement. Measuring supply volumes and consumption via metering gives utilities the base data to “audit” their supply on a daily, monthly or annual basis. This helps manage the supply and also indicates to the manager how much water is lost to leakage or poor accounting. The water audit process is the foundation for accountability in the water utility. While it is possible for a water utility to be accountable in its structures, but not very efficient in its operations, it is unlikely that a water utility can be efficient if it is not accountable. In order to achieve efficient operations in the water utility sector, the industry must be:
•Accountable – by employing sound, reliable water auditing as a routine business practice, and
•Efficient – by practicing effective water loss control
The Water Audit Process
The water audit process is similar to financial audits conducted by accountants, the water audit compares volumes of water treated and pumped to volumes consumed by customers, and other uses such as fire fighting and community uses. Estimated volumes of losses due to leakage and poor metering and accounting can be quantified in the water audit process. Currently, there is no national requirement for routine water auditing in North America, although several states have taken the lead in requiring periodic water audits by water utilities.
Water Loss Control
Water loss control includes utility efforts to manage leakage to economically low levels, and reducing metering and billing errors such that reliable measures of customer consumption are attained and sufficient revenue is garnered by the water utility.
CROATIAN CENTER OF RENEWABLE ENERGY SOURCES ( CCRES )