Kim Fisher
Director of Public Works & Utilities
Town of Cary
Speaking on October 29, 1998, about the water system issues of the $149 million February 2, 1999 Bond Referendum.
INTRODUCTION
"We are going to discuss: (1) why the water treatment plant expansion is necessary; (2) why the expansion is the best choice; (3) selecting the appropriate water plant capacity during that expansion; (4) what the expansion will cost; and (5) other water system bond projects."
"The first question we will entertain is why is expansion of the water treatment plant necessary. In answering that, we have to consider supply and demand. Our current water supply consists of the Cary/Apex Water Treatment Plant which gives Cary 11.33 million gallons of water per day. We purchase 4.5 million gallons of water a day from Raleigh, and 3.5 million gallons a day from Durham. That is a total supply of 19.33 million gallons per day, currently."
"As we graph this for the next ten years, we can see that in FY99, there is a slight increase from Raleigh (we have negotiated an additional 1 million gallons per day, from 3.5 to 4.5); we have projected in 2001 that we will need another 2 million gallons from Durham. In 2004, the new water treatment plant comes on line at approximately 22.5 million gallon capacity to Cary. By 2005, we expect to have it rerated with a final yield to Cary of 28.3 million gallons a day."
"When we look at demand, we look at historical records, typically. This is the historical record for calendar year 1997. The lower line is the points for each monthly average day; the upper line is the maximum day in that corresponding month. Between April and October, there is basically a 3.5 million gallon per day difference consistently across the middle part of the year. It’s for that maximum day that we design our water plant."
"Our water demands are forecast for the same period on these two lines. We begin with our current population and our current demands and extend out ten years. The upper line is our demand without the effects of our water conservation program, and the lower line is the expected demand with the effects of our water conservation program. Our water conservation program has already begun. We have goals to start experiencing the effects of that in the year 2000. By the year 2015, we expect to have a 20% per capita demand reduction."
When we plot the two lines together, water supply and water demand, we can see that the water supply is just incrementally above the water demand with conservation until you get out to 2004 when the water treatment plant comes on line; so, it’s a very close process right now of supplying water. "
"There are some benefits in this period before the water treatment plant comes on line of using water from other people. First, it helps delay the capital investment in the water treatment plant; second, it provides a future potential for regionalization with other water systems by interconnecting with those adjoining utility systems. It will provide protection against catastrophic failures in our system now and in the future through these interconnections. These interconnections provide a redundancy of supply for our customer base in the event of a catastrophic occurrence."
POPULATION
"The biggest part of our demand forecast for the future is based on our population projections. Our population projections are based on the current growth management strategies of the Town Council, and they are reflected in these numbers (see slide presentation). For the first three years of the period and then for the next three years of the period, you can see a tapering down in the percent change or percent increase in population."
OTHER WATER SUPPLY OPTIONS
"Other water supply alternatives that we have will be examined next. First, we have the ability to get water from the ground through deep wells and the second is from surface water. There are three major supplies for that. We get it from Raleigh, from the Neuse basin. We can get it from Durham which is also from the Neuse basin. Or we can get it from Harnett County which is from the Cape Fear basin. Another surface alternative is to expand the Cary/Apex Water Treatment Plant."
"Some pros and cons of ground water: Ground water is not regulated by the State in its use by municipalities; however, in Cary, there is very limited ground water available, and the quality of that water is not particularly good, and it is not a particularly reliable source. It has a high capital and operational cost per thousand gallons retrieved when using it as a municipal source. It has been attempted twice in the past and in both attempts has failed due to failure in both quantity and quality."
"Purchasing water from other systems: The purchase of water from Raleigh and from Durham is not regulated by the State since it is in the same river basin as Cary. This is known as no inter-basin transfer. The inter-basin transfer issue is quite a complex one, and I have some information in the lobby that will explain that in great depth. The detriment of purchasing water from Harnett County is that it is in the Cape Fear basin and would require an inter-basin transfer. Other detriments are that buying water from other local governments is not a long-term water supply fix. There are also problems with mixing water from other systems in quality, reliability and cost.
WATER FROM JORDAN LAKE
In looking at expanding the Cary/Apex Water Treatment Plant, first we look at Jordan Lake as a water supply. Jordan Lake has been designated by the state and the Corps of Engineers as having a safe yield of 100 million gallons a day for water supply and was designated by both the state and the Corps for the Research Triangle area. Jordan Lake is a reliable source of water, and the quality of water from Jordan Lake is as good or better as water from other surface water supplies in this area."
"The cost of producing water from Jordan Lake is the lowest that we have when we consider buying water. This chart shows the cost of producing water from the Cary/Apex Water Treatment Plant and the cost that we will expect in FY99 in purchasing water from Raleigh and from Durham. One detriment of expanding the Cary/Apex Water Treatment Plant is to use Jordan Lake as a water supply, it is highly regulated by the State of North Carolina."
"The next question I would like to address is in determining the appropriate water plant capacity. The first question I would expect to be asked is why a 16 million gallon per day increment, and not a smaller one. When we plan for expansion, there are six or seven parts of this complex issue which need to be examined. The first is the planning period, the next is anticipating future demands, the third is what is called the 80%-90% rule. The next is the time frame it takes to plan, design, permit and construct a plant. There are environmental and regulatory requirements, and then the plant has to meet the peak demands of the system."
"Water industry and EPA guidance suggests that a 15 to 20 year planning period for water treatment plant facilities is the standard period to plan for that facility. When we look at anticipating future demands, this is the same graph you saw earlier with the water supply and water demand trying to plan out here beyond 2008 to 2025 to when the next increment of expansion would possibly be needed, we are looking out to 2019 which gives us roughly a 15-year planning period."
"The 80/90 rule is basically this: At 80% of the plant’s capacity, planning for the next expansion should have begun. At 90% of the plant’s capacity, construction should have begun. If we look at this chart again, you can see at this level here, the plant was at 77% of the expansion that we are planning now and at this point here, we are at 90%. That’s when the plant would come on line. Looking out at the future and planning that time frame, that is following that 80/90 time rule. Our experience has been that it takes four years to permit a plant expansion and secure the water supply. Typically, design is concurrent with the permitting processing. After the permit is secured, construction takes another three years. If we go back to this chart, here we are planning in this time frame right here for the permitting and this time frame for the construction of the plant."
"The environmental issues that we have to deal with are both regulatory and environmental. The regulatory ones that will affect us on this plant come from the Safe Drinking Water Act, Disinfection Byproducts Rules, Phase 1 of those rules come into force in the year 2000 and phase 2 comes into force in 2003. We must meet those requirements by 2003 and those facilities are incorporated into the plant expansion to meet those regulatory requirements. In addition, the interbasin transfer and the Jordan Lake allocation process has some environmental requirements which will be incorporated into this plant design."
"The final issue is the ability to meet peak demands, the maximum day demand of the plant. When we combine the 80/90% rule with the time frames needed for the next capacity increase when we anticipate the future demand and the plant’s ability to meet the peak day demands, the increment selected was 16 million gallons a day which gives Cary the 15 year planning period before the next capacity increase is expected to be needed."
"The last topic I would like to present to you is the expected cost for the water treatment plant. To meet the regulatory compliance, we are looking at $13.4 million, for reliability issues $16.3 million, for the plant expansion, $40 million, for a total of $69.7 million. Of this Cary’s share is 77% (Apex’s share is 23%). The regulatory compliance is $10.3 million, reliability issues $12.6 million, and the plant expansion is $30.8 million for a total of $53.7 million."
"There is one other portion of the water system bond projects. This is four elevated water storage tanks which will cost roughly $10 million. These will increase the storage capacity for fire protection needs and to cushion our peak hour water demands."
You may Email your comments to Kim Fisher at kfisher@ci.cary.nc.us or call him at 469-4092.