(a) The Water Resources Planning Section will determine the percent growth for all applicable CIP projects using the following methodology.

The method involves the following three steps:

(1) Step 1 – Test for 100 Percent Growth. If flows/demands remained at June 1993 levels, would a project still be required?

(i) No: Growth = 100 percent.

(ii) Yes: Continue to Step 2.

(2) Step 2 – Test for Zero Percent Growth. Does the project improve or replace components of an existing facility without increasing the capacity of any of the components?

(i) Yes: Growth = zero percent.

(ii) No: Continue to Step 3.

(3) Step 3 – Determine Percent Growth.

(i) Identify system capacity added by the project.

(ii) Identify and subtract June 30, 1993, capacity deficit, if any.

(iii) Divide result by total project design capacity.

(b) Notes.

(1) For most water and wastewater facilities, there is a straightforward relationship between demand, capacity requirements, and facility size. For water transmission mains, however, the relationship is more complicated. There are many factors other than size which must be considered to determine capacity. These factors include length, the size and number of interconnections and the allowable energy differential between the points connected by the transmission system. Capacity analysis of a transmission network normally requires computer modeling. Previous water system analyses will be used to the extent they are applicable; however, where no previous analysis exists, computer modeling will be required.

(2) If an existing facility with available system capacity is being replaced by a new project which increases total system capacity, the available capacity in the existing facility is lost or wasted. In such cases, existing available capacity will be treated as a negative deficit in subsection (a)(3)(ii) of this section.

(c) Examples.

(1) An existing sewer has a safe capacity of 20 mgd. The June 30, 1993, peak flow is 17 mgd. A proposed parallel sewer will add 10 mgd of capacity for growth. Since the existing sewer can handle the June 30, 1993, flows the project is 100 percent for growth (subsection (a)(1) of this section).

(2) An existing sewer has a safe capacity of 20 mgd; its maximum capacity before overflow is 27 mgd. The June 30, 1993, peak flow is 21 mgd. A proposed parallel sewer will add 10 mgd of capacity for growth. Since the existing sewer can handle the June 30, 1993, flows, the project is 100 percent for growth (subsection (a)(1) of this section).

(3) An existing pumping station has 1 mgd of capacity. The June 30, 1993, flow is 0.8 mgd. A proposed replacement pumping station will have a total capacity of 1.5 mgd. The existing pumping station is old, and a rehab project would be needed if the new pumping station were not built. Therefore, the station is not 100 percent for growth (subsection (a)(1) of this section). It adds capacity, so it is not zero percent growth (subsection (a)(2) of this section). The percent for growth is calculated as follows: 0.5 mgd (the capacity added by the new pumping station) plus 0.2 mgd (the amount of lost available capacity) divided by 1.5 mgd (the total capacity of the new pumping station) = 47 percent (subsection (a)(3) of this section).

(4) An existing pumping station in good condition has 1 mgd of capacity. The June 30, 1993, flow is 0.8 mgd. A proposed replacement pumping station, located downstream to increase the service area, will have a total capacity of 1.5 mgd. The proposed pumping station is 100 percent for growth (subsection (a)(1) of this section).

(5) A pressure zone has a 1 mg storage deficit based on June 30, 1993, demands. When we finally get agreement to build a 3 mg tank in the zone, the deficit has risen to 2 mg. The tank is 66.7 percent for growth (3 mg added – 1 mg deficit)/3 mg total capacity = 67.7 percent (subsection (a)(3) of this section). (PD 93-01 § II)