April 9, 2008 > Water, the key to life (Part II)
Water, the key to life (Part II)
"When you drink the water, remember the spring."
This is the second and concluding installment of a two-part series that examines how the Tri-Cities receive water for domestic use and steps taken by Alameda County Water District (ACWD) to assure its quality and safety. Tri-City Voice recently met with ACWD General Manager Paul Piraino; Water Resources Planning Manager Eric Cartwright, P.E.; Operations Manager Walter Wadlow and Water Quality Manager Douglas Chin, P.E. to discuss ACWD operations.
From Part I:
Cartwright: We are fortunate to have multiple sources of water including ground water and San Francisco (Hetch-Hetchy) water to get through short term shortages. Our storage capacity of 150,000 acre feet in Kern County is close to three years of district demands. At this time we have approximately 125,000 acre feet stored.
Piraino: ACWD is well prepared for water challenges due to its 90 year history that began with a huge overdraft of the groundwater basin. The first goal was to correct that problem using recharge areas, rubber dams to divert local supplies and import water as a San Francisco Hetch-Hetchy customer and State Water Project contractor. There has been some very good planning starting in the 50's and 60's. We are very opportunistic about taking the maximum advantage of our local supplies. We have ground water desalination in addition to ground water. Our groundwater is practically back to historic levels. It has helped that we are a separate agency which has a single focus.
Wadlow: We talk about a diverse water supply almost as others might look at investments. Through a conscious decision, we are mitigating risk of shortages through a diversity of sources. Other water districts such as San Francisco and East Bay MUD have a "blue chip" source and rely almost exclusively on it.
In the event of a supply problem from other sources, we can draw from our groundwater on a short term basis. Last fall due to a dry year and Delta pumping problems, we took proactive measures so we could assure good supplies this year. We took some of our Semitropic storage starting last fall and maintained higher levels of local groundwater reserves. We also stored some of our water in San Luis Reservoir which is also part of the State Water Project. We are in pretty good shape to meet this year's system demands.
Piraino: If we get all of our supplies, we are in very good shape. We built and expanded our desalination plant early. It is the water supply from the Delta that is the wild card. We develop our Integrated Water Resources Management Plan - updated every two years - with projections of how the demand for resources will grow.
Wadlow: This assessment is incorporated in an Environmental Impact Report (EIR). There is a large effort, not always visible, to come to the conclusions shown in these reports. Water usage for some developments such as Fremont's water park will take a large amount of water initially, but then much of it is re-circulated. Newark's golf course has been in the planning process for quite a while so we have prepared for it. Water needs for the course will ultimately be supplied from a separate "purple pipe" or recycled water system. This is part of our long term planning.
Cartwright: The area where the A's development is planned was originally slated for commercial/industrial development. In our most recent forecast, we factored water usage under that demand load. We know now that it is changing to a ballpark, residential and retail/commercial. Are the water demands the same? At this time, we don't know.
TCV: What does ACWD do to make sure water is safe for human consumption?
Wadlow: One of the earliest reasons for treating water was the presence of bacteria, virus' and other pathogens in it, leading to disease. Filtering dirt and debris is important since pathogens can 'hide' behind those particles avoiding the actions of cleaning methods and agents. We also treat for a wide range of inorganic substances such as metals. Are there some things that water treatment does not remove? The answer is "yes." We put efforts not only into removing unwanted materials from the water when it arrives, but also trying to avoid the introduction of these materials into the water before it comes to us.
TCV: Is there a major difference between bottled water and ACWD water?
Chin: There may be differences in treatment but in terms of the regulations that apply to water, they are probably applied more stringently to public agencies such as ACWD. We need to respond and be accountable to the California Department of Public Health. ACWD monitors the water literally minute by minute and day by day. Bottled water manufacturers may be using reverse osmosis or granulated activated carbon or ozone which may give a different characteristic to the water but does not mean it is any safer. Both ACWD water and bottled water are required to meet the same drinking water standards. Environmental concerns however do occasionally arise about plastic water containers.
TCV: What about the recent concern of pharmaceuticals in drinking water?
Piraino: The Associated Press reporter who did the investigation noted that it is essentially a level playing field in this regard between bottled water and municipal water. In head to head tests, it is a matter of taste not quality.
Wadlow: Some claim that bottled water does not have a "chlorine" taste. However if you don't have chlorine in the water and do not store the water properly, things can grow in it. This is why it is a mixed bag as far as the public health issue is concerned.
We do not want even small amounts of pharmaceuticals or other contaminants in our water and would like the water from our sources to be free of these elements. We want the cleanest sources possible. To make sure these things are not in the water in the first place makes sense. Pharmaceuticals should be disposed of properly so they do not enter the water supply either here or upstream. It has not been demonstrated that the minute amounts of pharmaceuticals detected in water supplies has any adverse health effect.
Chin: Hetch-Hetchy water is basically pristine whereas water from the Delta is used by many other people doing all sorts of things. The California Department of Health requires a sanitary survey. The source is evaluated for contamination and what is necessary through a "multiple barriers" approach to protect public health. Different levels of treatment are required for water depending on the quality of the source. We have a laboratory on site and are testing all the time.
The water industry has been trying to address uniform quality throughout the country for many years. We are working with the regulators to develop information so they can know if any issues that arise are an imminent threat to public health. We are seeing these things come up because technology has advanced so that we can detect contamination at parts per trillion or quadrillion - numbers that are infinitely small. The real question is what is really significant and meaningful to public health.
Cartwright: Water agencies across the country vary in size and resources. At ACWD, we use technologies such as ozone and membrane filtration technology but if you look at other areas, some do not have the rate structure or supportive community that is willing or able to make the investment necessary for these methods. These are expensive technologies. Even though the regulations are in place, the ability to meet them varies just as school systems and roads vary. So far, this community has been supportive of a rate structure that lets us implement these types of technologies.