HomeMy WebLinkAboutWTR2700489(3) W-489 WEST HILL RESERVOIR WTR-'l 1
Engineering RepLrt on Joint Water System Faci-Jties
�Lq S`FaQaGe
BEGINNING
OF FILE
FILE TITLE
W- y 4w9
Ij leS`r U kleseP% 0,11 �
oN J o i tV�' Wai'eksy/S'�/�
�aci � i +ieS
City of Renton
King County Water Districts No. 14 and 63
Engineering Report
on
WEST HILL JOINT WATER SYSTEM FACILITIES
(Amendment to Comprehensive Water System Plan, October 1976)
RH2 ENGINEERING, P.S.
March, 1981
TABLE OF CONTENTS
SecLon I - Introduction . . . . . . . . . . . . . . 1
Purpose and Scope . . . . . . . . . . . . . . . 1
Summary and Conclusions . . . . . . . . . . . . . . . . 2
Section 11 - Service Area Water Demands . . . . . . . . . . . . . . 3
Population . . . . . . . . . . . . . . . . . . . . . . . . 4
1980 Demands . . . . . . . 4
Future Demands . . . . . . . . . . . . . . . . . . . . . 7
Section III - Water Supply, Storage and Transmission Plans . . . . 10
Joint Facilities - Renton Water Supply . . . . . . . . . . . . . . 10
Joint Facilities - Seattle Water Supply . . . . . . . . . . . . . 12
Joint Facilities - Recommended Plan . . . 12
Future Service - Adjacent Purveyors . . . . . . . . . . . . . 16
Alternate Renton West Hill System Improvements . . 17
Section IV - Financing and Implementation . . . . . . . . . . . . . . 17
Financing Plan . . . . . . . . . . . . . . . . . . . . . 20
Joint Service Contract . . . . . . . . . . . . . . . . . . . . . 21
Water Use Charge . . . . . . . . . . . . . . . . . . . . . . 23
Project Implementation . . . . . . . . . . . 31
I tST OF TABLES
Table 1: 1980 Water Supply from City of Seattle . . . . . . . . . . . 5
" 2: 1980 Peak Day Water Demands . . . . . . . . . . . . . . 6
" 3: Projected Water Demand for Year 2000 8
" 4: West Hill Joint Facilities - Proposed Design Criteria 9
" 5: Joint Facilities - Estimated Project Capital Cost . . . . . . . 13
" 6: It , Facilities - Estimated Annual Operating Costs . . . . 14
" 7: City of Renton Service Area - Independent Facilities
Estimated Fro;ect Capital Cost . . . . . . . . . . . . . . . 18
" 8: City of Renton Service Area - Independent Facilities
Estimated Annual Operating Costs . . . . . . . . . . . . 19
9: Joint Facilities - Proposed Financing Plan. . . . . . . . . . 22
10: City of Renton -
Current Cost of Water Supply and Transmission . . . . 24
11: city of Renton - Water Supply and
Transmission Cost including Joint Facilities . . . . . . 26
" 12: Proposed Basis for J^int Facilities -
Capital Cost User Charge . . . . . . . . . . . . . . . . . 28
" 13: Comparison of City of Renton Annual Costs
Joint Facilities Versus Independent Facilities . . . . . . . 30
r
LIST OF FIGURES
Figure 1: Study Area Boundary . Follows Page3
" 2: 1980 Peak Day Demands . . . . . . _ . . . . . 6
" 3: 2000 Protected Peak Day Demands . . . . . . . . . . . . . . 6
" 4: Regional Water Facilities - Renton Water Supply 10
" 5: Regional Water Facilities - Seattle Water Supply . . . . . . . . 12
6: Renton Service Area Water Facilities - Renton Water Supply . . . 17
SECTION I
INTRODUCTION
This report presents the results of a Joint Use Facilities Study for King
County Water District 014 and 63 and the city of Renton West Pill service
areas. RN2 Engineering was authorized to pruc..d with the study by the
city of Renton Council on October 24, 1980, acting on behalf of the city
and King County Water Districts 14 and 63. This report is prepared as an
addend" to the "Comprehensive Water System Plan" prepared by Narstad
Associates, Inc. in October 1976 on behalf of King County Water Districts
No. 14, 63, 69, 77, 86 and the city of Renton.
PURPOSE AND SCOPE
The primary objectives of the study were to recommend improvements
for: (1) A joint use storage facility so that each system can minimize
costs and avoid duplication of storage facilities, and (2) supply to each
system from the city of Renton wells in order that representatives of each
system can evaluate the desirability of such a supply scheme.
The scope of the study has included the following elements:
1. Review of existing distribution system improvements as
they relate to joint use facilities requirements.
2. Determination of 1980 water system demands.
3. Review of projected growth and determination of
future water system demands.
4. Identification and evaluation of water transmission and
storage facilities based on alternate city of Renton
water supply locations.
-1-
S. Identification and evaluation of water transmission
and storage facilities based on alternate city of Seattle
water supply locations.
6. Recommendation of a joint use facility plan based
on alternative evaluations.
7. Preparation of a proposed financing and
implementation plan.
The study results and recommendations are summarized below.
SUMMARY AND CONCLUSIONS
The study recommends implementation of a plan of improvements provid-
ing for the supply of city water ti the participants study area. A
1?00 gpm booster station, 1.0 million gallon reservoir and system of 12'
transmission mains will meet projected peak water demands and provide up
to 2500 gpm for fire flow. The recommended plan is less costly than
alternate plan using Seattle water and has other significant advantages.
The improvements should be owned and operated by the city of Renton.
Financing can be accomplished by revenue bonds and a state Referendum 27
Grant. Implementation will require agreement to a contract between the
city of Renton and Water Districts 14 and 63. The contract should include
the following elements:
1. Initial term equal to financing term and renewal options.
2. Water use charge for operation and maintenance costs with
provisions for annual adjustments.
3. Water use charge for capital costs of a fixed rate
terminating when bonds are repaid.
-2-
An initial user charge of $0.19 per 100 cubic feet for operation and
maintenance costs and $0.167 pe 00 cubic feet for capital costs will
provide an equi.able distribution of the project casts. The annual cost
to the city of Renton Will be approximately $25,000 to $32,000 less than
the annual coat of independent improvements. The city of Renton could
sell water to other adjacent water purveyors and increase this savings.
SECTION 11
SERVICE AREA WATER DEMANDS
The service area boundary considered in this study for the planniog
of joint water supply, storage, and transmission facilities is presented
in Figure 1. The area includes the current and anticipated service areas
of the three study participants. The service area boundaries of the
three participants as well as the adjacent water purveyors, King County
Water Districts No. 69, 77, and 88 are also shown in Figure 1. The city
of Renton service area included within the study area boundary differs
from the area identified in the 1976 Comprehensive Water Svstem Plan.
The portion of the Renton West Hill service area located south of Sunset
Boulevard has been excluded from the study area boundary. A major multi-
family development (Earlington Woods) is currently underway in this area
and service will be provided from the city's wells and the pressure zone
servicing the central business, the 196 pressure zone. No water demands
will be placed on the West Hill Joint Use Facilities to service this
development.
-3-
� r
o�
REN70N
Water Purveyor
Ey 8$ Service Area boundary
mi 14 Water District No.
r r, d • Study Area Boundary
�rr• .
r� 77`
n- r, Figure t
j Study Area Boundary
x�
POPULATION
Land use and zoning within the study area has been reviewed and re-
vised estimates of current and future population have been prepared.
These populations have assumed a 90% saturation development at proposed
land use densities occurring in the year 2000. The resultitg population
estimates are presented below:
Service Area 1980 200C
City of Renton 2,700 .1,400
King County Water District 14 1,200 1,300
King County Water District 63 2,500 2,6•"0
Total Study Area 6,400 7,300
1900 DEMANDS
Records of consumption and peak summer demands for each participant's
supply meter were obtained from the city of Seattle. 'fable 1 presents
tabulation of the monthly supply during 1980 to each of the participants'
service area. The daily per capita demands ranged from 73 to 85 gallons
with an average of 78 gallons. Total annual average demand was 345 gallons
per minute. Table 2 presents a summary of the 1980 peak day demands
based on consumption period of 12 midnight to midnight the following night.
The peak day was determined to be August 10, 1990. The tabulation presents
the peak day demand, the peak hour demand, and the ratio of these peak
day demands to the average annual demand for each participant and the
accumulated total of the three paiticipants. Figure 2 presents graphically
the daily variations in rate of water demand on August 10, 1980.
-4-
TABLE 1: 1990 WATER SUPPLY FROM CITY OF SEATTLE
(in hundreds of cubic feet)
Service Area
Month Renton KCWD 14 KCWD 63 Total
January 6,997 3,206 6,795 16,998
February 7,049 6,565 7,675 21.289
March 6,949 3,002 6,937 16,888
April 7,432 3,015 A,625 17,072
May 6,920 4,048 7,991 18,959
June 7,559 4,326 8,252 20,137
July 8,449 4,495 10,030 22,980
August 10,547 7,471 16,517 34,535
September 9,268 3,007 5,029 17,304
October 7,177 3,667 6,821 17,665
November 9,194 3,493 6,795 18,482
December 8,982 3,736 7,683 20,401
TOTAL 95,523 50,031 97,156 242,710
1980 Population 2,700 1,200 2,500 6,400
Average Water Demand 73 85 $0 78
(gallons per capita per day)
Average Water Demand 136 71 138 345
(gallons per minute)
TABLE 2: 1980 PEAK DAY WATER ➢EMAN➢S FROM CITY OF SEATTLE RECORDS
(August 10, 1980)
Renton KCWD 14 KCWD 63 _ Total
Total Water Demand 408,170 171,250 439,093 1,018,513
(24 bra. beginning
at midnight)
Average Peak Day Demand 283 119 305 707
(gallons per minute)
Ratio to Average Annual 2.1 1.7 2.2 2.0
Demand
Peak Hour Demaro 552 262 714 1,482
(gallons per minute)
Ration to Average 4.1 3.7 5.2 4.3
Annual Demand
-6-
200o
2000
7Total --
ri
1500 f
ap"
O a 1500
z 0
Total— z
,OODZ I C "p — — ——
LL 1000
Boson A8
5O0 „�/\ ': / f
/ Soo �.;........ .r:
Renton 1 : W-D.63 j
D BaM W.D. 4 .
M N o `--- - _.W.D.14
BPM p M __—_--_.____
HOUR OF DAY 6AM N 6PM M
HOUR OF DAY
I
Figure 2
Figure 3
1980 - Peak 2000 - Projected
i
Day Demands Peak Day Demands
F1'Tl1RE DEMANDS
Each participant's projected demands for the year 2000 are presented
in Table 3. The projections have assumed that the average annual demand
per capita will increase to 100 gallons by the year 2000, and peak day
characteristics for each of the participants will be similar to 1980.
1, lure 3 presents graphically the anticipated variations in demands dur-
ing the peak day in the year 2000. Table 4 presents proposed design cri-
teria for the West Hill Joint Facilities based on these projected demands.
The criteria established a proposed supply and storage capacity needed to
meet the projected demands. Minimum water surface elevations are estab-
lished for the increments of storage in orde• 'o provide adequate pressure
at the highest elevations within each of the participants' service area.
Future demands of the adjacent water purveyors included within the
1976 Comprehensive Water System Plan are of interest in exau.ining the
feasibiiity of providing future service to these purveyors from the pro-
posed joint facilities. A detail.d analysis has not been made of the
land use or current populations of these three purveyors. However, based
on population data presented in the 1976 report and the assumption that
peak water demands are simil,, to the combined existing demanns of the
three participants, the following year 2000 water demands were determined.
Population . . . . . . . . . . . . . . . . . . . . . 4,100
Average Annual Demand - gallons/capita/day 100
Average Annual Demand - gallops pei minute . . . . 285
Maximum Day Demend - gallons per micute . . 583
Peak Hour Demand - gallons per minute . . . . . . . 1,224
The joint use facility modifications required to meet these additional
water demands will also be discussed in this report.
-7-
TABLE 3: PROJECTED WATER DEMANDS FOR YEAR 2000
(90% of Saturation Development)
Renton RCWD 14 _ RCWD 63_ Total
Fcpulalion 3400 1300 2600 7300
Average Annual Demand 100 100 100 100
(gallons/capita/day)
Average Annual Demand 236 90 181 507
(gallons per minute)
Peak Day Demand 491 151 400 1042
(gallons per minute)
Peak Hour Demand 956 307 92. 2165
(gallons per minute)
_g_
TABLE 4: WEST HILL JOINT FACILITIES
Proposed Design Criteria
Design Population 7,300
Average Annual Water Demand
Gallons per Capita 100
Gallons per Minute 50;
Peak Day Demand
Gallons per Minute 1,042
Peak Hour Demand
Gallons per Minute 2,165
Fire Flow
Gallons per Minute 2,500
Proposed Water Supply Capacity
Gallons per Minute 1,200
Proposed Storage Capacity
Equalizing in Gallons 245,000
Fire Reserve in Gallons 300,000
Total 545,000
Minimum Storage Water Elevation
Domestic Demands 47,9.5
Domestic 1 Fire Demandr 460.5
Storage Overflow Elevation 495.0
_q_
SECTION III
WATER SUPPLY, STORAGE AND TRANSMISSION PLANS
This section presents alternative plans for the construction of water
supply, storage and transmission facilities required to wet the projected
demands of the three participants. While the principal objective of this
report is the investigation of joint use facilities using the city of Renton
supply, we have also examined an alternative based on supply from the city
of Seattle. These alternatives are presented below with our recommendations.
Additional requirements for service to adjacent purveyors ate also dicussed.
The last alternative presented is extension of the city of Renton water
system to supply its West Hill service area independent of other purveyors.
JOINT FACILITIES - RENTON WATER SUPPLY
This plan proposes the supply of Renton water from its 196 service
zone. The proposed plan of improvements is presented in Figure 4. The
improvements include a booster station to pump from Renton'c 196 service
zone to the proposed 495 zone established by the overflow elevation of
the proposed joint storage facility. Several locations were examined for
the booster station and connecting transmission main to the city's trans-
mission pipeline on Rainier Avenue. The location shown in Figure 4 was
determined to be the most economical and practical. Acquisition of pro-
perty for the booster station will be required.
Two sites were investigated for the location of a joint storage fa-
cility. The first site, owned by the City of Renton, -a located at 84th
Avenue South at the approximate intersection of South 128th Street. This
site has an approximate ground elevation of 387. In order to provide
-10-
Trans eh' aFn m
']Ili•. '` /
s
f 7F
} f S ► ar '
y M,*n
CohneCtl
Nancy. LEGEND
,' •{ ',� ! +. r ' j' • — - EXISTING WATERRlAIN
_ / 4/rj NEW WATERMAIN 6 SIZE
•N 1 _ A BOOSTER STAT-ON
to rd ' _ /C 1; f • METERED CONNECTION
.• UNMETERED CONNECTIO
i f� _ • r '' ,t 1 \. � t N • .� � S10RAGE RESERVOIR
_ a ♦ - - Figure 4
Regional Water Facilities
� ' ,�. :,y � � �:� / i. : •./ . '; .``�` Renton Water SuPPIY
adequate storage -t a proper elevation at this site, a 1.7 mg reservoir
(standpipe) with a 108-foot water depth is required. An elevated tank
at this site is substantially higher in cost than a standpipe.
The recommended storage site is located on property owned by the
Renton School District at the intersection of 80th Avenue South and South
1:4th ltreet. The ground elevation a, this site is approximately 430.
Storage required would be a,,_ imately 1,000,000 gallons with a water
depth of 65 feet. The reduced volume and height of the reservoir signifi-
cantly decreases its cost relative to the alternative site. The reservoir
in this location will assure a more stable service pressure for normal
domestic and irrigation use of the adjacent Thompson School and Dimmit
Junior High School. The reservoir and large transmission main serving the
reservoir will assure proper fire flow is available to both schools.
Transmission mains have been sized using reasonable velocities during
conditions of expected demands and to assure adequate pressure at the con-
nections to each participants' system. Metered connections have been pro-
vided to Water Districts 14 and 63, anc unmetered connection to the city's
West Hill distribution system based on the assumption that the city will
own and operate the ioint facilities. :he plan further proposes to main-
twin an existing metered connection to the city of Seattle water supply
at 84th Aveoue South using the Water District 14, 8" main to convey water
from the city of Seattle on an emergency basis to the joint facilities.
Estimated project capital costs and ope-ation and maintenance costs
are presenLed under the discussion of the recommended plan.
-]1-
JOINT FACILITIES - SEATTLE WATER SUPPLY
A plan for joint facilities supplied by the city of Seattle is pre-
sorted in Figure S. The plan indicates a new, metered connection to the
city of Seattle Cedar River Pipeline at 84th Avenue South. A booster sta-
tion is proposed at this location incorporating facilities for controlling
the rate of supply. The booster station is necessary to meet the hydraulic
requirements of service area during all pressure conditions on the
Cedar River Pipeline at the point of connection. Flow control will be
itilitzed to maintain peak supply rates below 130% of the average supply
during the peak days to avoid demand charges.
The storage facilities for this alternative are identical to those
proposed under the Renton supply alternative.
Transmission mains have been sized using the same criteria as in the
Renton supply alternative. Metered connections are proposed to each of
the distribution systems. Estimated capital, operation and maintenance
costs are presented for each alternative.
JOINT FACILITIES-RECOKKENDED PLAN
The estimated project cost of each of the alternative joint facility
plans is presented in Table 5. These estima es are based on current costs
for similar work and are subject to revision based on the completion of a
preliminary design. The estimated costs of the joint facilities with Renton
supply are slightly less than those with Seattle supply.
Table 6 presents an estimate of the joint facilities operation and
maintenance costs in the year 1981 and 2000. These estimates are based
on current (1981) costs _or labor, materials, and services. No attempt
has been made t evaluate increases in cost due to inflation. The 1981
-12-
2U� ( pi.
New Itttetered Connection
to Seattle Supply Main
Seattle Cedar^
P s� y
s� `t2� R ~ .�ivar- . t�PIY Main
KD l4 Meter " 19 Uf • 1 j 130d er,Stt�tiot
.- with " Coon 01
-Cprtnrre�Can � �; Rated (.Ap9eity
!° LEGEND
r �.,, '�' ✓Y r' LS iNEW WATERNAIN&SITE
•+ �/' ;> ' { '•' �' rvdir. " BOOSTER STATION
• � � •u :• y w METERED CONNECTION
F Jon ectibn •- h�F� ♦ � �� _ • STORAGE RESERVOIR
A.
t 1 . '•, .j s_ �'' .
♦ fi'4 . Figure 5
Regional Water Facilities
' ' ` : Seattle Water Supply
M7
TABLE 5: JOINT FACILITIES
ESTIMATED PROJECT CAPITAL COST
Renton Water Supply Seattle Water Supply
Unit Price 2uaratity Amount (QuanLLU Amount
A. Transmission Mains
1. 12" D.I. Main in place $ 25/LF 8700 LF $ 217.500 9900 LF $ 247,500
2. 12" Gate Valves in place 1,600/EA 9 EA 14,400 10 EA 16,000
3. Surface Restoration 3/FT 1700 LF 26,100 9900 LF 29,700
4. Metering & Connections 10,000/EA 3 EA 30,000 6 EA 60,000
5. Connections Only 1,500/EA 2 EA 3,000 -0- -0-
6. Renton Ave. St. Crossing -0- -0- 1 EA 5,000
Subtotal $ 291,000 $ 358,200
B. Booster Station
1. Site Work and Piping L.S $ 10,000 L.S. $ 10,000
2. Structure L.S. 49,000 L.S. 36,000
3. Pumps and Mitors in Place
Renton 3 @ 600 Rpm, 60 HP L.S. 55,000 -0- -0-
Seattle 2 @ 1200 gpm, 25 HP -0- -0- L.S. 25,000
4. Mechanical L.S. 15,000 L.S. 20,000
5. Electrical L.S. 25,000 L.S. 15,000
6. Telemetry and Control System L.S. 17,000 L.S. 22,000
Subtotal $ 170,000 $ 128,000
C. StorsAe reservoir 1.0 MG, 52'/, 65' Height
1. Foundation, Sitevork and Piping L.S. $ 70,000 L.S. $ 70,000
2. Steel Reservoir in Place L.S. 235,000 L.S. 235,030
3, Painting L.S. 45,000 L.S. 4S,000
Subtotal $ 350,000 $ 350,000
Subtotal Construction Cost $ 811,000 $ 836,200
Sales Tax and Contingencies 15Y- 121,650 125,450
1ota1 Construction Cost $ 932,650 $ 961,650
D. Indirect Coat Allowance 20X+ 187,350 $ 192.350
E. Total Project Cost $1,120,000 $1,154,000
1981 Present Worth)
-13-
TABLE 6: JOINT FACILITIES
Estimated Annual Operating Costs
Renton taster Seattle Water
Supply Supply
1981 2000 1981 2000
1. Purchase of Seattle Water -0- -0- $ 51,500 $75,500
($0.212 per 100 CF)
2. Cost to Supply Renton Water $41,300 $60,600 -0- -0-
to the Joint Facilities
($0.17 •)er 100 C0
3. Labor 7,800 7,800 9,500 9,500
4. Power 8,800 12,900 1,200 1,800
5. Repairs and Replacements 7,300 7,300 6,400 6,400
6. Other 1,200 1,200 1.200 1,200
Total S 66,400 $89.800 $ 69,800 $94.400
Present Worth 1981 (8%) $700,200 $136,000
-14-
present worth of the operation and maintenance costs based on 8% interest
rate, is $700,200 for the Renton water supply alternative and $736,000
for the Seattle water supply alternative.
Economic comparison of the two alternative joint facility plans
results in a 1981 present worth of the Renton supply alternative of
$1,920,200 and the Seattle water supply alternative of $1,890,o00.
There are several advantages that are associated with the Renton Supply
alternative. These are enumerated below.
1. The city of Renton's desire to provide supply to all city
residents from the city's sources.
2. The city of Renton's supply maintains high quality during
all periods of the year, and adequate quantity is available
in the Cedar River aquifer to meet the foreseeable needs of
the city including Water District's 16 and 63.
3. Water from the Renton supply is less aggressive than the
I
city of Seattle's, resulting in less corrosion of steel
materials and leaching of cement and asbestos fibers in
asbestos cement water mains.
4. The city of Renton supplies are groundwater sources and
therefore are less subject to future treatment requirements
Than the surface water supplies of the city of Seattle.
These advantages, together with a slightly lower total cost ($69,800)
result in the recommendation to the participants that the joint facilities
plan using the city of Renton water supply be constructed.
-15-
FUTURE SERVICE.=ADJACENT PURVEYORS
We have examined the recommended joint facilities plan to determine
the capability to meet the projected demands of King County Water Districts
69, 77, and 88. The capacity of the booster station supplying the joint
facilities must bb_ increased from 1200 to 1800 gpm to provide supply to
the adjacent purveyors. An additional booster station with a normal supply
capacity of 600 gpm with fire pump capabilities of 2000 gpm will be re-
quired at the site of the proposed storage reservoir. This booster sta-
tion, in combination with the existing elevated storage of King County
Water District 69 and 71, will provide adequate capacity to meet peak
demands and fire flow requirements of the adjacent purvevors. Service
to the adjacent districts can be accomplished without reducing the cap-
ability of maeting the demands of the three participants. Additional
transmission facilities will be required from the storage site to the
i
adjacent district's systems. An examination of the transmissi an system
of the recommended plan under conditions of service to the adjacent pur-
veyors indicates ro measurable adverse affect on service pressures at the
point of connection to the three participants' distribution systems.
In summary, the recommended joint use plan can accommodate the future
water demands of King County Water Districts 69, 77, and 8E with the
addition of improvements discussed.
-16-
ALTERNATE RENTON WEST HILL SYSTEM IMPROVEMENTS
A plan of improvements to meet the city's West Hill service area
demands has been developed as a basis for the city to compare its partici-
pation in the joint facilities. Further, this alternative is a plan which
can be implemented should the three participants fail to proceed with the
recommended joint facilities. The plan of improvements is set forth in
Figure 6. The improvements are similar to those of the recommended plan
except that the storage reservoir is proposed to be located on the city's
existing site. This site is preferred as it is located within Renton's
service area and at the point of highest service elevation. The proposed
storage reservoir will have a volume of approximately 870,003 gallons with
an overflow elevation of 480. Water depth of the reservoir would be apporxi-
mately 93 feet with an overall height of approximately 98 feet.
The booster station will he at the same location as the recommended
joint facilities plan. Rated capacity of the booster station will be
600 gpm. Transmission mains 12" in size are proposed.
The estimated cost of improvement to the city's West Hill service
area is presented in Table 7. Operation and maintenance costs for these
facilities are presented in Table 8.
SECTION IV
FINANCING AND IMPLEMENTATION
A discussion of the proposed financing plan, contractural relation-
ship between the three participants, cost to be borne by each of the parti-
cipants, the method of recovery of these costs and a preliminary schedule
of steps necessary to the implementation of the project is presented here.
These proposa,s are suggestions for a method of proceeding with this joint
-17-
-Connection to Existing -* •"�• "'"
' on TransmissioQ Men14
t r.
Renton Distribytion - 4.
System Conrw..tions
ion_
LEGEND
r r 4
R} yrx^'�r. -�i�`t. ,� j f ' �♦ —'q— EXISTING WATERMAir:
e vyF. ..T. '•1 J �12 NEW WATERMAIN& SIZF
IJ 1 r k' A BOOSTER STATION
�_ •�iA } IYI �, STORAGE RESERVOIR
,r ky. ' { I TAT. +a a (:'ii UNME T FRED CONNECTION
fife•-( �'f• ( .!J ! I
LZ
Figure 6
} " Renton Service Area
�. Water Facilities
�� � � Renton Water Supply
TABLE 7: CITY OF RERTOR SERVICE AREA
Independent Facilities Estimated Project Capital Cost
A. Transmission Mains
1. 12" D.I. Main in Place 3900 LF @ $25 $ 97,500
2. 12" Gate Valves in Place 4 ea @ $1600 6,400
3. Surface Restoration 3900 LF @ $3 11.700
4. System Connections 3 ea @ $1500 4,500
Subtotal $120,100
B. Booster Station
I. Sitework and Piping $ 10,000
2. Pump House 36,000
3. Pump and Motors in Place
2 ea @ 600 gpm, 60 HP 38,000
4. Mechanical 15,000
5. Electrical. 20,000
6. Telemetry and Control System (local) 17,000
Subtotal $136,000
C. Storage Reservoir 0.87 MG, 40'0, 93' height
1. Foundation, Sitework and Piping $ 72,000
2. Steel Standpipe in Place 211,000
3. Painting 45,000
Subtotal $328,000
Subtotal Construction Cost $584,100
Sales Tax and Contingencies is%. 87,600
Total Construction Cost $671,700
D. Indirect Costs Allowance 20% $134,300
E. Total Project Cost $806,000
-18-
TABLE 8: CITY OF RENTON SERVICE AREA
Independent Facilities Estimated Annual Operating Costs
1981 _ 2000
1. Cost of Supply Renton
Water to Vest Bill Boaster Station $ 16,200 $28,200
2. Labor 7,800 7,800
3. Power 3,500 6,100
4. Repairs and Replacements 6.500 6,500
S. Other 1,200 1,200
Total $ 35,200 $49,300
Present Worth 1981 (8%) $378,400
-19-
project. Special requirements of each participant or other participant
constraints my require modification of the proposal or the development
of alternate "thods for the project implementation. It should be pointed
out that the proposed project c 'fers a substantial improvement in water
service to the study area and in particular provides significant benefits
by providing adequate storage and transmission capabilities to meet fire
flow demands. While the participants' motivation in participating
these joint facilities may be the current demand charge by the city o:
Seattle, the substantial benefits the project provides to water service
in the study area should be carefully considered in the decision of
participation and implementation of this project.
FINANCING PLAN
We propose that the joint facilities be owned and operated by the
city of Renton. The city has the credit rating and the financial capa-
bility to provide the most economic cost of financing. Further, the
city of Renton has the trained staff, equipment and resources for opera-
tior. of the facilities proposed and currently operates a number of facili-
ties of identical complexity and size.
Concurrent with this study, the city of Renton, on behalf of the
participants, has made preliminary application to the Department of Social
and Health Services for a Referendum 21 grant to fisist in the financing
of the project. This preliminary application has been approved and a
request to submit a final grant application has beeen received. The fin-
ancing plan anticipates that the city will be successful in obtaining a
state grant in the amount of 40% of the direct construction cost. The
facilities proposed are of a regional character and have the capability
-20-
for expanded service to adjacent purveyors. These facilities generally
receive a high priority rating under the Department of Social and Health
Services rating system and usually are fu:ded.
The balance of the project cost can be financed by revenue bonds from
the city of Renton. We hsve assumed that the revenue bonds will be serial
bonds issued for a period of 30 years with a coupon interest rate of _0%.
We further anticipate that a financing cost of approximately 3% of the amount
of the bond issue will be required. Table 9 prevents a summary of the pro-
posed financing plan. The state grant is comp-',,d to be $354,000 with the
balance of the project costs to be financed, of $766,000, requiring a revenue
bond issue in the amount of $790,000. The average annual principal and
interest repayment requirements for the revenue bonds are computed to be $87,500.
JOINT SERVICE CONTRACT
We propose that a relatively simple contract be entered into between
the city and Water Districts No. 14 and 63. The contract would provide for
service by the city of Renton to King County Water District No. 14 and 63
for an initial contract period of 30 years (life of the revenue bond
issue) and with provisions for contract extensions. The contract would
provide for service by the city of Renton from the joint facilities based
on a service charge per hundred cubic feet of water delivered to each
participant from the joint facilities.
The service charge would be composed of two parts. The first part
would be the charge for operation and maintenance costs of the city related
to the supply of water through Renton's existing system and the joint
facilities. This charge would be established initially in the contract
and subject to annual revision based on a prescribed formula.
-21-
TABLE 9: JOINT FACILITIES
Proposed Financing Plan
Construction Cost
$885,000
Less State Crant @ 40%
Of Construction host
$354,000
Local Share of
Construction cost
$531,OOo
Washington State Sales Tax 5.4%
$ 47,800
Indirect Costs
$187,200
Total Local Capital Cost
$766,000
Financing Cos[s
$ 24,000
Amount of Revenue Bonds
$790,oOO
Annual Revenue Bonds
Pr. ncipal & Interest
M years Serial Bonds $ 87,500
at 10% Interest)
-22-
The second part of he charge would be a rate per one hundred cubic
feet representing a partial recovery of the annual principal and interest
coat of the city of Renton required to repay the bonds issued for financ-
ing of the joint facilities. This charge would be fixed initially and
remain constant over the life of the revenue bonds. At such time as the
revenue bonds were repaid, this charge would be discontinued. A prelimi-
nary determination of these two water use charges is presented below.
WATER USE CN_4RCE
Operation and Maintenance
The charge established for recovery by the city of Renton of its
operation and maintenance costs must include the city's current
cost of operating and maintaining its water supply and transmission
system, including current financing costs associated with these
facilities, and the cost of operation and maintenance of the joint
facilities. We propose that this operation and maintenance charge
be established based on the total cost of the items identified
relating to the total Renton water system consumption. We believe
this is reasonable since the facilities will be an integral part of
Renton's total water supply system.
Table 10 illustrates a determination of the city's current
cost of wvater supply and transmission. This tabulation is eased on
information presented in the recently completed "Water and Sewer
Rate Study" for the city of Renton by Peat, Marwick, Mitchell and
Co. , December 1980. The tabulation is based on the 1981 estimates
presented in this report. The items of post include operation and
maintenance costs associated with production and transmission, a
-23-
TABLE 10: CITY OF RENTON CURRENT COST OF WATER SDPPLY AND TRANSMISSION
(Based on "Water and Sever Rate Study,"
City of Renton. December 1980, 1981 Estimate)
Water Consumption, Cubic Feet x 100 2,506,000
(From Table IV-2)
Water Supply 6 Transmisssion Coats
(From Table V-3)
1. Production and Transmission $285,641
2. Allocated General and Administration $ 48,044
Subtotal $333,685
3. Less 1981 Coats of Seattle Water for
Renton West Rill Service ($ 30,000)
Subtotal $303,685
4. Allocated Existing Debt Service
without Coverage (42%) $107,048
5. Allocated State Excise Tax $ 15,338
6. Total Water Supply and Transmission Cost $426,071
7. Total Watt: Supply and Transmissior, Cost
Per 100 CF $ 0.17
-24-
prorated allocation of general and a4ministrative cost, an allocation
of existing debt service to supply and transmission facilities and
a computed amount of state excise tax related to these items.
Deducted from these costs are current estimated 1981 costs of the
city of Renton for purchase of water supply from the city of Seattle.
These costa are based on the city of Seattle current water rates
including the demand charge for the West Hill in 1981. The total
1981 estimated water supply and transmission cost is $426,071.
Based on so estimated consumption for 1981 of 250,600,000 cubic
feet, the total water supply and transmission cost per 100 cubic
feet is $0.17.
Table 11 illustrates a determination of the cost of Renton
water supply and transmission including the operation of the joint
facilities. This determination is based on 1981 operation estimates.
The existing city-wide water supply and transmission costs are
added to projected costa for supply to the joint facilities and the
operation and maintenance costs fee the joint facilities, to arrive
at a mew total water supply and transmission cost of $492.431. The
additional consumption of Water Districts 14 and 63 raises the
total 1981 consumption to 265,300,000 cubic feet. The total water
supply and transmission costs per 100 cubic feet is determined to
be $0.19. We propose that this rate be established as the rate to
be charged for operation and maintenance to Water Districts 14 and
63 per 100 cubic feet of water obtained through the joint facilities.
This rate would apply if the facilities were in operation in 1981.
Adjustment to this rate would be made in the following manner
-25-
TABLE I1: COST OF RENTON WATER SUPPLY AND TRANSMISSION
INCLUDING OPERATION OF JOIN FACILITIES
(Based on 1981 Estimate)
Existing Water Consumption CF x 100 2,506,000
Additional Watt; Consumtion
Water Distrusts 14 and 63 CF x 100 141,000
Total Water Consumption CF x !00 2,653,000
Existing Water Supply and Transmission Cost $426,071
Addition to Existing Costs for Supply
to West Rill $ 41,260
Additi- l Operation and Maintenance
Costs for West Hill Facilities $ 25,100
Total Water Supply and Transmission Cost $492,431
Total Water Supply and Transmission Cost Per 100 CF $ 0.186
Use $ 0.19
-26-
The operation and maintenance rate of $0.19 per 100 cubic feet would
be based on the city of Renton past year (1980) water system and
operation and maintenance cost (exclusive of principal and interest
on debt service, depreciation and city imposed taxes) divided by
the total water consumption for the same period. Prior to the 1st
of March, 1982, the city of Rent.on's 1981 costs woulJ be determined
.n a similar manner. The percentage increase in the cost per 100
cubic feet of water consumption would be applied to the operation
and maintenance rate and the rate adjusted beginning March 1st of
1982. Annual adjustment: would occur in a similar manner during
each year in which the contract is in force.
Capital Recovery
The basis for recovery to the city of Renton of a portion of the
capital costs of the joint facilities is presented in Table 12.
The proposal is based on Water Districts 14 and 63 being responsible
for the incremental increase in the city of Renton's cost between
Rerton's estimated cost for independent facilities to service its
West Rill service area versus the cost of joint facilities. State
grant funds are then applied proportionately to each entity's cost.
The results of this proposal indicate an annual cost of $24,500 to
be borne by Water Districts 14 and 63, which, based on 1981 antici-
pated water use results in a user rate of $0.167 per 100 cubic feet.
Since the city of Renton is obligated to the major share of
the cost of these facilities, it is proposed that this rate remain
constant through the life of the revenue bonds issued to finance
-27-
TABLE 12: PROPOSED BASIS FOR JOINT FACILITIES
CAPITAL COST USER CHARGE
Total Renton Water Districts
Cost Cost 14 and 63 Cost
Construction Cost $885,000 $637,300 $247,700
Less State Grant
40% of Construction Cost $354,000 $254,900 $ 99,100
Local Share of
Construction Cost $.531,000 $382,400 $148,600
Washington State Sales
Tax 5.4% $ 47,800 $ 34,400 $ 13,400
Total Local Share of
Construction Cost $578,800 $416,800 $162,000
Indirect Cost $187,200 $134,800 $ 5_,400
Total Capital Cost $766,000 $551,600 $214,400
Financing Cost $ 24,000 $ 17,300 16,700
Total Amount of
Revenue Bonds $790,000 $568,900 $221,100
Annual Bond Principal
and Interest (30 Year Serial
Bond at 10% Interest) $ 87,500 $ 63,000 $ 24,500
Water Districts 14 and 63
User Charge Based on 1981
Consumption at 14,700,000
Cubic Feet $0.167/100 CF
_Y8_
the facilities. Increases in water use by Water Districts 14 and
63 would increase the income to the city of Renton and further
defray its share of financing the improvements. Further, it is pro-
posed that the city of Renton is free to negotiate contracts with
adjacent districts for the use of these facilities subject to no
adverse affects to service to Water Districts No. 14 and 63.
Combined User Charge
The initial combined user rate to King County Water Districts 14
and 63 would be $0.357 per 100 cubic feet. Based on estimated 1981
water consumption of 14,700,000 gallons from the joint use
facilities, the annual cost would be $52,479. The purchase of a
similar quantity of water from the city of Seattle, including the
calculated 1981 demand charge for King County Water Districts 14
and 63, will amount to an annual 1981 cost of $47,486. The differ-
ence in annual cost is a small amount relative to the significant
additional benefits to be derived from joint improvements. Further,
the proposed contract establishes a fixed manner in which the charges
will be computed and assures an equitable charge to Water Districts
14 and 63 and an equitable recovery of expenses to the city of Renton.
The city of Renton is bearing the major portion of the cost
under the proposed contract and user charge relationship discussed
above. It is appropriate to examine the city of Renton's alterna-
tives as compared to participating in the joint project on the basis
proposed. In Table 13 we have prepared a comparison of annual costs
to the city of Renton for participation in the joint
-29-
TABLE 13: COMPARISON OF CITY OF RENTON ANNUAL COSTS
JOINT FACILITIES VERSUS INDEPENDENT FACILITIES
Indnendent Facilities Joint Facilities
Year Year Year Year
1981 2000 1981 2000
A. Captial Costs _-- -"
1. Project Cost $806,000 $1,120,000
2. Less State Grant -0- $ 354,000
3. Net Project Cost $806,000 $ 766,000
4. Financing Cost $ 25,000 $ 24,000
5. Amount of Revenue Bonds $831,000 $ 790,000
6. Annual Principal & Interest
(30 years, Serial, 10%
interest) $ 92,000 $92,000 $ 87,50C $ 87,500
B. Operating Costs
1. Existing Water Supply
& Transmission Cost $ 16,200 $ 28,200 $ 41,300 $ 60,600
2. Project Operating Cost $ 19,000 $ 21,600 $ 25,100 $ 29,200
3. Total Operating Cost $ 35,200 $ 49,800 $ 66,400 $ 89.800
C. Total Annual Cost $127,200 $141,800 S 153,9DO $177,300
D. Less Cost of Seattle Water
Purchase at Current Rates
(Renton Only) ($ 30,000, ($ 52,100) ($ 30,000) ($ 52,100)
E. Less Sale of Water to
Water Districts 14 and 63
at $0.357 per 100 cubic feet -0- -0- ($ 52,500) ($ 67,900)
F. Net Annual Cost $ 97,200 S 89,700 $ 71,400 $ 57,300
-30-
facilities versus the construction and operation of independent fa-
cilities for its west Hill service area. The costr shown indicate
net increases in annual operating costs for the years 1981 and 2000
for each of the alternatives. The deduction of the cost of the pur-
chase of Seattle Water is based on the tact that the current city
operating costs include this amount, and increases in this cost
would occur in the year 2000, should either of the projects not be
constructed. A cost comparison shows a substantial benefit to
Renton's participation in the joint facilities on the basis
proposed.
PROJECT IMPLEKENTATIOM
The initial steps in the implementation of the proposed joint facili-
ties project include the development and agreement to a contract for par-
ticipation betveei the city of Renton, King County Water Districts 14
and 63. Since Renton is the proposed owner and will support the major
part of the financial burden, the initial agreement to proceed in accor-
dance with this report must come from the city of Renton Council.
Following Renton's determination to proceed in accordance with the pro-
posal, acceptance to the contract terms moat be agreed to by King County
Water Districts No. 14 and 63, and a contract document prepared for
final signature. Concurrent with this task it is our recommendation
that the city proceed with a final application for grant funds from the
Department of Social and Health Services.
At such time as a basis for contract has been agreed upon and the
city has received indications that the grant will be favorably acted
upon, engineering should be initiated to accomplish the preliminary
-31-
design of the project. Concurrent with the preliminary design of the
project, the city should initiate acquisition of property required for
the construction of the booster station and reservoir site.
Accomplishment of the above should allow the city to proceod with
the preparation of final construction plans and specifications. The pro-
ject can then be bid within the time constraints associated with the
grant offer. Construction of the project is anticipated to require
approximately nine months, depending somewhat upon equipment deliveries
and the schedule for the erection of a steel standpipe.
The above is a brief outline of the major implementation tasks
required for the project. A more detailed schedule and budget for these
tacks can be prepared once the city and Water Districts 14 and 63 have
reviewed this report and have concurred in principle with the implementa-
tion of the project.
-32-
WTR'- II StoRas-e� Faue.i /i #i
ENDING
F FIL
FILE TITLE
411
We4 Mi 11 k 5e.0 Oo io �
En� i �veeei�6- �ePo�
oN Ten i #0+ "R Sysfe►�
Far. I- eS