•

•

ANG

010 KOOTZNAHOO HEAD WATER RESOURCES STUDY

ANGOON, ALASKA

Alaska Power Authority LIBRARY COPY

PREPARED BY:

Jay Farmwa1d, P.E. Design Engineer

ENVIRONMENTAL HEALTH BRANCH ALASKA AREA NATIVE HEALTH SERVICE

ANCHORAGE, ALASKA

MAY 1981

10: 1479B/50c LR: 101481

. -.

.,

-"

,-" ...

.. .'

~ ~

t KOOTZN A HOO HEAD .1

j " WATER RESOU RCES STUDY "j.

f May, 1981 r

t .~

~ ,

t Prudhoe 8ay

I I , I

, I , I

·1

A LASKA CANADA

• Fa inanka

, • ,

Gulf Df Aloska

TABLE OF CONTENTS

PAGE

.5l.IMMARY.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. • • • • .. .. .. .. .. • • .. .. .. .. .. .. .. .. .. .. .. .. • .. • .. .. .. .. .. .. .. .. .. .. • .. 1

RECOMtvtENDATIONS.. • • .. .. .. .. .. • • • • .. .. .. • .. .. • • • .. .. .. .. .. .. • .. .. .. .. .. .. .. • .. .. • .. .. .. • .. .. .. .. .. .. .. .. .. 5

I.. INTRODUCTION.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 6

1.1 Authorization 1.2 Scope Of Study 1.3 Acknowledgements 1.4 Datum Note

6 6 6 6

II.. STUDY AREA..................................................................................................... 7

2.1 Location 2.2 Topography 2.3 Climate 2.4 Government 2.5 Land 2.6 Transportation 2.7 Power 2.8 Waste Disposal 2.9 Economy 2.10 Population

7 7 7 9 9

10 10 11 11 13

III. EXISTING WATER SUPPlY AND DISTRIBUTION SYSTEM •••••••••••• _ •••• I5

3.1 History 15

3.1.1 Source Development 15

3.1.1.1 Groundwater 15 3.1.1.2 SUrface Water 16

3.1.2 Transmission Line Development 17 3.1.3 Appurtenance Development 20

3.1.3.1 Treatment Plant 20 3.1.3.2 Water Storage Tank 21 3.1.3.3 Distribution System 21

3.1.4 Summary of Projects 21

3.2 Summary Of Existing Facilities 23

3.2.1 Water Source 23 3.2.2. Transmission Line 23

3.2.2.1 Kootznahoo Head 23 3.2.2.2 Submarine Line 23 3.2.2.3 Angoon Line 24

J

~ ,

., .

:~

.'

- ------.----------- ----'-------

, 1

•

•

•

TABLE OF CONTENTS: (Cont.)

4.4 TRANSMISSION LINE

4.4.1 Requirements 4.4.2 Alternatives

4.4.2.1 Existing Basin 4.4.2.2 Lake McCarroll

4.5 APPURTENANCES

4.5.1 Treatment Plant 4.5.2 Storage Tank 4.5.3 Distribution System

PAGE

50

50 51

51 52

52

52 54 55

V. COST ESTIMATES FOR ALTERNATIVES .......•..•••••••.•••.•••..... 56

VI. DISCUSSION OF ALTERNATIVES ••••.•••••••••••••••••••••.••••••••• 59

VII. REFERENCES .........•..•..•....•••••.•••..•.•..••••.•......•••. 60

APPENDICES

A.

B.

C.

D.

E.

USGS Report on Kootznahoo Inlet

Hose Design (1966)

Ductile Iron Pipe Design Notes (1968)

Diving Notes (1969)

Norton Corrosion Report on Cathodic Protection System

-'

• . . !

} ' ..

.', _ I

, !

'-. ;

, . i

SUt+fARY

This report is a compilation of data developed by the United states Public Health Service for several of the more viable domestic water supply alternatives on Kootznahoo Head. Information was taken both from existing files/reports and field surveys conducted during 1980 and 1981.

The two (2) water supply alternatives addressed in detail were: 1. Existing basin/reservoir - accurate definition and potential

.improvements. 2. Lake McCarroll (located approximately one mile NE of the existing

reservoir) - development potential.

-While the primary objective was to make recommendations with respect to developing adequate capacities, comments have also been offered on transmission line, appurtenance, and distribution system improvements.

1 lt is hoped that the findings and recommendations presented here will aid the Community of Angoon in making decisions ~ith respect to water system

1 improvements and/or future requirements. ,

Existing System: The domestic water source for Angoon is a small reservoir impounded by a log crib dam on Kootznahoo Head. Oirectly above this dam are two (2) beaver dams, which provide additional natural storage. The 7,000 foot transmission line from the reservior to the 100,000 gallon wood stave storage tank consists of 3-inch and 4-inch pipe. Oue to the length of this line and the numerous bends and jOints in the 1,000 foot section which crosses beneath Kootznahoo Inlet, the maximum delivery capacity to the treatment plant is 70 gpm. water treatment consists of pressure sand filtration, chlorination, and fluoridation. Two (2) booster pump stations, one on the Angoon beach, the other (duplex operation) in· the water treatment building, supplement the 102 feet of static head between the reservoir and tank high water level. Conventional pressure distribition is achieved with ductile iron, asbestos cement, PVC, and galvanized steel water mains.

- 1 -

, t

•

Design and water Source Alternative Data: Design Flows - The basis for this study was a projected population of 800 by the year 2000 and a per capita water demand of 75 gallons per person per day. Evaluation of water source alternatives and appurtenance design assumed a maximum daily demand and fire flow demand of 84 gpm and 500 gpm respectively. Any significant industrial development in Angoon will require that these flows be adjusted upward. Note also that an arguement can be made for increasing water supply to promote development, if such growth is an objective of the

community.

Existing Basin/Reservoir - A determination of the watershed area and runoff characteristcs indicate that the minimum required reservoir storage should be on the order of 4.9 million gallons. Data collected for this study suggest that the log crib dam impounds 1.1 million gallons, while the beaver dams store an additional 4.9 million gallons. Total existing storage then, is 6.0 million gallons or 18% more than the projected requirement. Note however, that during periods of low runoff it may be necessary to manually divert water from the beaver ponds to the water supply reservoir. Based on the driest period on record the maximum yield of this reservoir was estimated to be 120 gpm or 43% more than the design maximum daily demand. There is, however, a leak estimated at 100 gpm along the toe of the dam. This becomes significant during dry periods. While the dam should be repaired, it need not be raised or replaced unless the beaver dam/population is jeopardized for some reason. In such an event, consideration should be given to adjusting the spillway elevation upward 3 to 4 feet.

Yield of the watershed is approximately 230 gpm (maintaining this flow in the transmission line would require raising the dam 8 feet).

Lake MCCarroll - The Lake MCCarroll watershed is approximately 960 to 1,280 acres in area. Applying local runoff relationships to this basin it was determined that little or no storage is required for the assumed demand flows. Sounding data on lake McCarroll revealed a maximum depth of 45 feet with an estimated total volume of 160 million gallons. Altimeter data indicate that head conditions at this site would be very comparable to those at the existing reservoir.

-2-

1 I

Maximum yield of this basin based on the driest period on record is approximately 775 gpm. Because the reservoir (lake) is several orders of magnitude larger than the recharge this basin could ever support, the "practical" maximum yield of the reservoir is also 775 gpm. With respect to water transmission, the development of Lake McCarroll would require 3,600 to 11,800 feet of new pipeline, depending on the selected routing. Note that the storage effected by this lake would make it possible to eliminate fire and regulating storage requirements in town. However, transmission line design would then have to accommodate the higher peak flows i.e., 8-inch line would probably be required.

Preliminary cost estimates for those two (2) pipeline alternatives including reservoir development, are $585,000 and $1,137,000 respectively.

Transmission Line, Appurtenances, and Distribution System: Transmission Line - The existing transmission line is capable of delivering 70 gpm to the treatment plant when the line is in good repair. However, gasket failures in the submarine Barco joints and corrosion of the steel

sections along the beach are a recurring problem; at times, losses to the inlet have been as high as 40 gpm. This line is the major limitation in the

, existing system. Redesign of the submarine joints and increasing the pipe diameter to 4 or 6 inches will be the single most effective step in achieving the design flows. Depending on the redesign of the marine sections, other portions of the transmission line mayor may not need to be upgraded to 6 inch or 8 inch diameter.

Appurtenances - The only modifications to the existing treatment plant which should be considered are the reduction of system head losses through piping/filter redesign. This mayor may not be economically feasible depending on the redesign of the transmission line.

Additional water storage tank requirements to accommodate fire flows and emergency storage are on the order of 80,000 to 100,000 gallons.

- 3 -

i

pistri~ution System - Based on the projected design flows it is clear that fire demand will govern ~ny rehabilit~tien ef the exi$ting eistribution system.

Initial calculations indicate that 8-inch pipe would be optimal. Ductile iron ~s the recommended material as it is better able to withstand point and beam Ip~ds th~n pl~stjc or ~sbe$tos cement.

•••

.~

"t >

-~-

.. ·t

•

•

RECOMMENDATIONS

Assuming a design population of 800 with little or no industrial water requirements, and in light of the estimated costs and benefits to be derived from the alternatives addressed in this report, there is little basis for abandoning the existing reservoir system. However, certain improvements to the reservoir, transmission, storage, and distribution systems should be made. The following prioritized recommendations address these improvements.

Short Term: Estimated Cost

1. Design new beach and submarine line. $ 34,000

2. Perform detailed hydraulic analysis of entire transmission line to size the submarine, beach, and land based sections. 7,000

3. Construct new beach and submarine line. (Assuming crossing location remains the same.) 266,000

4. Repair leak in existing dam. 50,000

5. Repair leak in water tank. 10,000

6. Upgrade land based portions of transmission line per (il2) above. 530,000

7. Install gaging station on Stromgren or McCarroll Creeks. 25,000

SlIBTOTAL $ 922,000

Long Term:

8. Upgrade distribution system to B-inch 0.1. $ 430,000

9 • . Construct additional BO,OOO gallon storage tank. 110,000

10. Reduce head losses through water treatment plant. 128,000

11. Use data in this and other Angoon water resource studies to make decisions with respect to the community's water supply.

SUBTOTAL $ 668,000

GRAND TOTAL ~115901000

- 5 -

,

1 , j

SECTION I INTRODUCTION

1.1 Authorization: This study was undertaken by the U.S. Public Health Service (PHS) as part of a continuing effort to provide technical assistance to the community of Angoon under Public law (P.l.) 86-121. PHS recognizes the unique water supply problems in Angoon and hopes the data developed in this report will aid community planners/decision makers in planning water supply improvements. It should be stressed that there are no funded P.l. 86-121 projects currently underway in Angoon and the potential for future rederal funding under this ·program for all Alaskan Native communities is limited. However, other funding sources may well be available and this information should be useful in preparing project proposals for such funds.

1.2 Scope of study: The primary objective of this study was to evaluate and make recommendations with respect to domestic water supply source capacities on Kootznahoo Head. This involved a more accurate definition of, and recommended improvements to, the existing basin reservoir system and an assessment of the potential for developing lake McCarroll, which is approximately 1 mile NE of the existing reservoir.

Comments have also been offered on transmission line, appurtenance, and distribution system improvements.

1.3 Acknowledgements: This study would not have been possible without the valuable assistance and recommendations offered by the Community of Angoon. Special thanks go to Gary Eddy, PHS rield Engineer; John Thein, PHS Maintenance Specialist; John McCarroll and Al Mitchell, PHS Co-step Engineers; and Bill Baily of Angoon, who all worked very hard to collect the field data presented here.

1.4 Datum Note: ~ll elevations in this report are referenced to a punch mark on the old Chatham Road hydrant (elevation 21.24 feet), which is the datum for the Angoon water system.

- 6 -

,

SECTION II STUDY AREA

2.1 Location: The City of Angoon is located on Admiralty Island in Southeastern Alaska near the tip of a relatively low, narrow peninsula (Figure 1). Angoon is on the southwestern side of the island at latitude 57°29'45" north, longitude 134°35' west, approximately 65 air miles south of Juneau and 41 miles northeast of Sitka. The town itself is bounded by water on two sides, Kootznahoo Inlet to the east and Chatham Strait to the west.

2.2 Topography: The local topography is characterized by low rolling hills which rise up from the beach area. These are densely covered with spruce, pine, hemlock, and underbrush. Surface soils consist of 2 to 4 feet of organic overburden with underlying clays. Bedrock is generally eQcountered 2 to 26 feet below grade. This rock is a folded or faulted schist material, which usually requires blasting for utility installation.

2.3 Climate: As for most of Southeast Alaska, Angoon's climate reflects the maritime influence of the Gulf of Alaska. Precipitation levels are, however, significantly lower than those recorded in other areas throughout southeast due to the shadowing effect of the Baranof Mountain Range.

Mean annual precipitation in Angoon is 38-inches with the heaviest rainfall occurring in October. Snowfall averages 63-inches, the heaviest amounts falling during January and February.

The mean annual air temperature is 41°F, reflecting the mild winters (8500 0 F-dayslyear). Winter temperatures seldom get below zero and are more commonly above 20°F. Similarly, even though 70°F temperatures are common in the summer, the maximum recorded temperature is only 77°F.

- 7 -

..------

, '

• 1

I • , i

,I I

1 ,

1 I

I

I 1 I

~ I i,

, I I ., , ., I

"

AI

.,

C')

~ ~

'I ~ ~

~

\n -\ :Q

):.

-\

ANGOON

' ..

ADMIRALTY

ISL AND

'. Bay

o 5 - -- - -

Gambier Bay

FIGURE I ~ ________ ~L-__________________ ~

• ~ ..... .t-•• _, ... _._~ .. -!; __ 4·.,. ...

I

1

I I j

!.

I I i I f

,

2.4 Government: There are a number of governmental and quasi-governmental entities in Angoon, which provide a range of community services for some 500 residents. These include the City of Angoon, the Angoon Community Association, the Alaska Native Brotherhood, the Alaska Native Sisterhood, the Angoon Tlingit and Haida Community Council, Kootznahoo Inc., and the Angoon Boat Owners Association.

Angoon is a second class city incorporated under Alaska law and oper~ting with a mayor/council form of government. In addition to elected offiCials, the city has a staff which is responsible for administering municipal policy prescribed by State law and local option. This staff is responsible to the Council and, at present, consists of a city administrator, clerk, secretary, planning coordinator, treasurer, a police chief, fire chief, and water and sewer superintendent. Not all of these positions are salaried.

2.5 Land: In 1927 the Angoon townsite was surveyed by the Bureau of Land Management. Of the 37.35 acres surveyed, 22.7 acres were not subdivided, effectively confining the town's development to less than 15 acres of land. This pattern of development is changing as the townsite trustee has turned over the unsubdivided townsite area to the city.

As a participating Native village under the Alaska Native Claims Settlement Act, the Angoon ~illage corporation (Kootznahoo Inc.) has received surface ownership to 23,040 acres of land in the Angoon area. The corporation, in turn, must transfer at least 1,200 acres of that land to the City of Angoon. Further, the 1980 Alaska Lands Act (0-2) set aside Admiralty Island as a National Monument. There are provisions in the Act which allow use of the restricted areas by Angoon for -traditional purposes."

-9-

-" .

,. I ,

1

2.6 Transportation: Transportation to the City of Angoon from the larger trade centers in Southeast Alaska is dependent on air or water modes. Oaily scheduled air service by light float plane is now available six (6) times a week. These planes are limited to passengers, mail, and light, non-bulky type objects. Chartered aircraft are freauently utilized, but this service is relatively expensive. Bulkier or heavier

. goods must be moved to the City via scheduled barge service or hauled on the larger fishing craft. The State ferry system, which calls on Killisnoo Harbor, has scheduled summer service several times a week.

2.7 Power: Electrical energy is supplied to Angoon and the surrounding area by the Tlingit and Haida Regional Electrical Authority (THREA) with offices in Juneau, Alaska. Power is generated by three (3) small diesel-electric units (865 kw total capacity), located in Angoon. There are no transmission interties to Angoon.

THREA's current rate is as outlined in the table below:

CURRENT ANGOON ELECTRICAL RATES

Class of First Over Minimum Fuel State Service 300kw 1,500kw 300kw--l ,500kw Bill Surcharge Assistance

Residential .3808 .3338 23.23 .0043 .130642

Small commercial .3808 .3338 38.08 .0043 None

Large power .3690 .3221 354.79 None None

NOTE: All rates are in $/Kw.Hr. except minimum bill, which is a flat monthly rate ($).

In conjunction with the Alaska Power Authority, Angoon is currently

investigating several alternatives to conventional diesel fired power generation. These include: (a) Tidal energy; (b) Hydroelectric energy; ~nd (c) Waste wood energy. Reference five (5) contains more detailed information on the preliminary studies accomplished to date.

- 10 -

1

, I (-

, i

1

•

•

•

•

2.8 Waste Disposal: A conventional gravity sewer system serves the majority of Angoon. There is one submersible lift station in town which ties the lower sections of main into the treatment plant. Secondary treatment is accomplished using a septic tank for primary clarification, a rotating biological contactor (bio disk), and secondary settling basin. An ocean outfall is provided for the effluent, which has historically been one of the best throughout Southeast Alaska. In the present configuration, average daily flows are practically limited to 60,000 gpd.

2.9 Economy: By and large, the economy of Angoon has always been based on the fishing industry. However, due to heavy losses in a 1961 Hood Bay cannery fire, poor fishing seasons, debts, lack of facilities, and competition from other fishing boats, this industry has not provided a strong economic base for Angoon in recent years.

At present, the nearest fish processing plant from Angoon is located at Chatham, across Chatham Strait on Chichagof Island.

The fishing industry in this part of the State of Alaska has traditionally centered around the harvest of Salmon. As this resource .has been depleted, some emphasis has shifted to the harvesting of Dungeness crab and Halibut. These species are of considerable commercial value and appear numerous within the area.

An expanding maFket for these species may revitalize Angoon's fishing economy.

There are several longer range projects which the City of Angoon is considering to stimulate economic growth and, therefore, income and employment in Angoon. As could be expected, most of the projects are related to the fishing industry. Some of these are: a co-op type business to market different species of fish, a cold storage facility for freezing and storing fish, developing and marketing fish foods and fish by-products, establish markets for Native foods, an aquaculture Industry, fish hatcheries, and other fish related industries.

- 11 -

•

Most of these projects have been itemized in past Overall Economic Development Program (OEDP) progress reports.

The village corporation (Kootznahoo, Inc.) will play an important role in the economic development of Angoon. Kootznahoo Inc. is the organization which will supervise and manage the land that it received under the Alaska Native Claims Settlement Act. The use of the surface resouces on the land selected by the village corporation will be determined by that organization, with ownership of subsurface resources vested in the regional corporation, Sealaska Corp.

The land which has been selected under the terms of the Alaska Native Claims Act contains commercially valuable timber stands. Rough projections show that of the land selected by Kootznahoo Inc., 15,000 acres contain commercial grade timber. Assuming 32,000 board feet/acre and a 100 year maturation period, the annual harvest has been estimated at 4.8 million board feet.

This alone would not be large enough to support a pulp or sawmill (the Alaska Lands Act precludes logging other areas on the island). It may be possible for Angoon to sell its available timber resource or consumate an agreement with other communities in the area to establish a regional logging/mill operation. In any event, a good docking facility and storage area would have to be constructed, probably adjacent to the existing ferry terminal and marine warehouse at Killisnoo Harbor.

With this present socia-economic lifestyle of the Natives, they may choose to leave the forest in its present condition and not harvest the timber resource. The village corporation's selections have been made with both the commercial timber and recreational values of the Angoon area in mind; allocation of the resource between these values has yet to be determined.

Because Angoon is isolated from commercial areas in Alaska (accessible ~y by sea-plane or boat), it is extremely difficult to entice industry to locate there unless the area has a valuable resource to offer.

- 12 -

• 1 I

, 1

JI

•

Unfortunately, Angoon with its relatively small population does not offer a large, available work force for attracting industry. Therefore, the ilMlediate future prospect for improving the employment situation in Angoon does not appear very promising •

2.10 Population: Population data for Angoon is shown in Figure 2. Rises in the last 10 years can be directly attributed to the increased availability of housing, specifically the 55 Turnkey units built in 1975

and 1976. While the Tlingit-Haida Housing Authority and the City of Angoon have plans for future housing projects, no definite schedules have been established to date.

In light of potential new housing, a limited forest products industry, and stabilization of the fishing industry, a population projection of 800 may not be unrealistic for the year 2000. This figure then, will be the design population used throughout this report in planning for future water supply needs.

-13-

-'

- -- ----.- ----- --- - --- ---- --- ----r'!'T

..

800

700

GOO

Z 50 o !;i ~40 => Q.. o

0

v

Q.. 30 0

20 0

10 o-

0

..

,

.

-

.........

~ ~ ~

r

1880 1890 1900

ANGOON POPULATION

//

4..~/ /

~1P /

CJ~>' ~~'j

/

/ V

./ '-

/J ~

I '~ I 1910 1920 /930 1940 1950 1960 1910 1980 1990 2000

YEAR

FIGURE 2

SECTI~ III EXISTING WATER SUPPL V

AND DISTRIBUTION SVSTEM

3.1 History: The existing water supply and distribution system in Angoon is the result of six (6) Public Law 86-121 projects undertaken from 1958 to 1979. A narrative on IHS's involvement in developing Angoon's water system follows.

3.1.1 Source Development: 3.1.1.1 Groundwater: Originally, it was thought that groundwater

mdght be the solution to Angoon's water shortage problems. In 1958 two (2) wells were drilled for the state school which had a total yield of 12 gpm and produced water of marginal quality. In 1960, prior to the first P.L. 86-121 project, emergency funds were appropriated to locate a groundwater supply for the ~unity. In this project, three (3) test wells were drilled at various locations in the community. None of the wells produced the minimum required yield of 10 gpm.

In 1963 Angoon was approved for an accelerated Public Works Project, to be administered under P.L. 86-121. In the spring of 1963, a community water and sewer system was designed based on the premise of a groundwater source. The approach of further exploration for a groundwater source was adopted after consultation with the Groundwater Branch of the U.S. Geological Survey (USGS). They recommended that wells be driven in the area of the school, where previously limited quantities of water were obtained. It was hoped that combining the yield of two (2) or more wells would provide an adequate water supply.

-15-

3.1.1.2

•

,

This approach was undertaken during August through October 1963. Three (3) wells were drilled. The first well produced 0.5 gpm, the second was dry, and the third produced one gpm. Upon completion of the well drilling, the USGS prepared a report which suggested other possible water sources. It was felt that an economical groundwater source may be in the buried beach gravels under muskeg swamp areas about 1-1/2 miles from the village. This source could possibly be developed by driving 2-inch well points to a depth of 30 to 40 feet in these gravels.

In February 1965, the Public Health Service rented a small core-drill to investigate these beach gravels. Three (3) holes were attempted, but solid rock was ~ncountered at a depth of 10 to 12 feet. At this point, further attempts to seek groundwater were abandoned and another source was sought.

Surface Water: Stromgren Creek is fresh water mountain stream across Kootznahoo Inlet from the townsite of Angoon. This water source is fed from a small lake on Kootznahoo Head. The basin is in an isolated location and is subjected to little human contamination. In 1966, it was determined that an adequate watershed existed and

that although the water was high in color, due to organic tannins, the supply would be adequate as a domestic source throughout the year.

To develop this source, a dam site was selected on the creek near the outlet of an existing lake. This site allowed a log crib dam to be keyed into the rock abutments and its elevation would provide sufficient head to transmit water across the inlet by gravity .

- 16 -

,

Particular emphasis in design was placed on obtaining a gravity flow system in order to minimize operational costs to the village. A transmission line 4,000 feet long would transmit the water to the turn point shore of Kootznahoo Inlet; however, crossing Kootznahoo Inlet with a pipeline was not considered to be an easy task. This tidal inlet has currents which exceed 18 feet per second (12 miles per hour). Installing and securing a conventional steel or cast iron pipeline in the inlet was considered to be a costly undertaking.

3.1.2 Transmission Line Development: In March 1965, the PHS secured the cooperation of the USGS in undertaking a reconnaissance survey of Kootznahoo Inlet to determine the bottom configuration, type of bottom, and current velocities in the tidal channel (Appendix A).

While the design for the inlet crossing was being developed, construction on the water and sewer project began in September 1965, on both sides of Kootznahoo Inlet. The major part of the work took place during the 1966 construction season. Installing the land portion of the transmission line on Kootznahoo Head was not an easy task. The line crossed a large swamp, along with many rock areas. About 1,000 L.F. of rock was encountered which required drilling and blasting. Constructi~n in Angoon correspondingly involved extensive rock excavation and installation of water and sewer mains along reaches of existing sea wall bulkheads.

The submarine pipeline crossing design (Appendix B) was developed by providing several leading rubber hose manufacturer's that information obtained in the reconnaissance survey of the inlet. They, in turn, analyzed their particular hose product to determine if it had the flexibility to follow the irregular channel bottom, the durability to resist abrasion on the rocky inlet floor, and also have sufficient weight to eliminate excessive anchoring.

- 17 -

I J

,

The submarine hose was purchased for approximately $19,000 from the Gates Rubber Company, Denver, Colorado. It was installed in June 1966, but remained unused until the transmission line from the dam to the inlet shore was completed in early October 1966.

In October 1966 the water was turned on to fill the water tank. Less than two weeks later, the hose broke. The break was repaired with an extra length of hose that was on hand. However, the hose broke again about ten days after it had been repaired. Further repairs of the hose were not attempted. Although the basic idea of using a rubber hose was logical, as it would conform to the rock bottom, the weight of the hose was not adequate to prevent movement and it physically wore out during its short life.

Later calculations made during the design of a steel pipe crossing revealed that the hose was subjected to 11 pounds/L.F. lift and 11 pounds/L.F. drag forces, while the respective restraining forces were half of these values. These forces resulted in the hose acting as a moving "cork screw" along the bottom.

After the 1966 hose broke, a second manufacturer was contacted for a preliminary design on another submarine hose. This design was submitted in April 1968, but abandoned due to lack of installation recommendations and performance guarantees.

Several alternate methods of crossing the inlet were investigated at this time. Each of these crossing methods were compared with the oil pipelines in Cook Inlet as to installation and operational problems because of similar tidal conditions at these two locations. In December 1968, a contract was developed using 6-inch ductile iron river-crossing-pipe. The line was to be laid in a 2,400 foot "U" shape towards Chatham Strait where the tidal velocity conditions were more suitable (Appendix C). The bids were opened in March 1969 with a low bid of $239,000. This contract was not awarded. The excessive costs of this contract were attributed to possible problems involved in installing the

- 18 -

.'

, • ",

•

•

1 j

line and whether the flexible jOints would take the stresses expected during installation. The flexible joints would flex 15 0

in all planes of motion, but were subject to possible damage when stressed at full deflection .

The channel was then investigated by a Government diver to find a location where the deflection of the flexible joints could be predicted before construction. In March 1968, a crossing location was found 1,000 feet towards Chatham Strait from the previous hose crossing (Appendix D). This location was near the base of the previously discussed "U" shaped pipeline. The location had a lateral fault crossing the inlet which would provide some protection for the pipe. Another design was submitted for contract in June 1969. This crossing was to use extra heavy steel pipe with 900 elbows and swivel joints at variable spacings. The joints were spaced according to the bottom configuration and estimated tidal velocities in each portion of the channel.

The swivel jointed steel pipe contract was advertised in June 1969, and the contract was awarded in August 1969. Low bid was $85,600. The contract was later amended to include the shore lines at an additional cost of some $18,000.

Construction on the crossing started September 29, 1969, and was substantially completed on October 20, 1969. A direct current forced cathodic protection system was installed on the steel lines in January 1970. Minor repairs on a pipeline electrical connection were completed by a diver in February 1970, and the ~ipeline contract was completed on March 8, 1970.

When the system was started in October 1969, the distribution

system was found to be in a poor state of repair. This was attributed to the system freezing in previous winters. Leaks in the distribution system resulted in it demanding the maximum flow through the supply system. During the 1969-70 winter, the City of

- 19 -

3.1.3

Angoon began to find and repair these leaks. As they were repaired, the consumption of water dropped from 70 gpm (maximum gravity flow rate) to 21 gpm.

In 1970 it was found that the cathodic protection system on submarine line was not working properly. Investigation revealed that tidal currents were abrading the coating on the interties between the flexible joints and wearing the polyethylene coating off the anode bed header cable. The cathodic system, anode bed, and interties along the pipeline were redesigned during the summer of 1970, and changed during August 1970. The interties were replaced with 3/8-inch stainless steel aircraft cable, and the anode bed was moved into slacker water by the Angoon shore.

The system has be~n~function~ng in this basic configuration since that time. Ili~Zv,'the land based portion of the transmission line was extended to the new 100,000 gallon water storage tank using 4-inch ductile iron.

Appurtenance Development: 3.1.3.1 Water Treatment Plant: The original water treatment

building was brought on line in October 1969 and provided the following treatment: a) l/20-inch in line "Y" strainer. b) Chlorination by a hydraulic-operated chlorine pump. c) Fluoridation by a hydraulic-operated fluoridation

pump.

In 1975 a new facility was completed which housed two pressure sand filters, a chlorinator vat, fluoride vat, and duplex booster pump station. In 1977 an additional booster pump was installed in a small pumphouse on the Angoon beach. The additional head provided by this pump 1s practically limited by the available Net Positive Suction Head (NPSH).

- 20 -

I

•

3.1.3.2 water storage Tank: Head and contact time were provided by a 20,000 gallon wood stave tank in the initial system (1969). In 1974 a new 100,000 gallon wood stave tank was constructed in a new location above the Turnkey Housing project. This tank, which is currently in use, provides system pressures in the 30 to 35 psi range.

3.1.3.3 Distribution System: Throughout the six (6) PL-86-121 projects in Angoon numerous changes and additions have been made to the distribution system. Ductile iron, asbestos cement, PVC, and galvanized steel mains ranging in size from 1-112-inch to 6-inch diameter currently serve the community.

3.1.4 Summary of Projects (Water):

PROJECT NO.

AN-63-339

AN-68-680 AN-70-690 EM

AN-72-928

CONSTRUCTION PERIOD FACILITIES INSTALLED

1965-1966

1968-1970

1973-1977

Dam, Kootznahoo Head transmission line, rubber hose submarine line, Angoon transmission line, water treatment building, 20,000 gallon tank, 2,500 feet of 4-inch AC main with seven (7) hydrants serving 60 homes.

steel submarine line with flex barco joints, cathodic protection system.

New water treatment building- with sand filter, 100,000 gallon tank, 1,650 feet of 4-inch DI transmission line, 3500 feet of 6-inch DI main with five (5) hydrants to upgrade existing distribution system and serve 30

. new TK (III) Phase I homes .

-~-

PROJECT NO.

AN-75-134

AN-77-l80

CONSTRUCTION PERIOD FACILITIES INSTALLED

1974-1978 550 feet of 6-inch DI main with three (3) hydrants to serve 25 new TK (III) Phase II homes.

1979

-22-

Water service line to elderly housing site (not yet constructed.)

•

•

3.2 Summary of Existinq Facilities: 3.2.1 water Source: The water source for Angoon is a 1.1 million-gallon

reservoir impounded by an earth/rock fill dam (spillway elevation 271.6 feet) on Stromgren Creek, approximately 1.25 miles from Angoon on Kootznahoo Head. This log-crib structure has a 35 foot long crest and stands 12 feet above grade at its greatest depth. Directly above the storage dam are located two (2) beaver dams which store an additional 4.9 million-gallons. These two (2) storage impoundments are fed by surface runoff from a 280 acre watershed. Flow from Stromgren Creek has reportedly been steady even during the driest weather on record. These and other data on the watershed/reservoir which were developed for this study will be presented in detail in Section IV. Gravity flow from the dam to the water treatment plant (elevation 83 feet) is practically limited to approximately 70 gpm due to head losses in the transmission line.

3.2.2 Transmission Line: 3.2.2.1 Kootznahoo Head Transmission Line: From the dam on

Stromgren Creek, water is transmitted through 500 L.F. of 4-inch wood stave pipe and 4,300 L.F. of 4-inch plastic pipe to the Turn Point shore of Kootznahoo Inlet. Depth of bury of this line is 4 feet minimum. A meter pit is located approximately 480 feet before the line reaches the mean high water level on this side of the inlet.

This pit also contains an air vacuum and pressure relief val ve. >{' Jot 1.. u- w"J i -::, +-n~'--'>~

3.2.2.2 Submarine Transmission Line Across Kootznahoo Inlet: The transmission line across Kootznahoo Inlet consists of three sections. The two beach lines (2,139 feet total) are 3-inch 1.0. schedule 40 steel pipe with 125 pound flange joints at 42 foot spacings coated with 10 mils of "Scotch Kate". The first 50 feet on the Turn Point side and the last 50 feet on the Angoon Side are 200 psi flexible hose. The crossing consists of 990 feet,

- 23 -

2.3-inch 1.0. extra double strong steel pipe with 49 BARCO Type N ball joints and 21 GRAYLOC quick couplings (Figure 3). The gaskets on the ball joints are of molded asbestos composition. The numerous 90 0 in elbows allow the pipe to conform to the irregular channel bottom (rigure 3A). The beach and submarine line are under cathodic protection from a rectifier located on the Angoon shore. Details on this system are contained in reference 2.

3.2.2.3 Angoon Line: This portion of the transmission line is 4-inch PVC (750 feet) to the water treatment plant and then 4-inch Dr to the water tank (2,030 feet).

3.2.3 Appurtenances: 3.2.3.1 Treatment: The following processes are used to remove

turbidity, disinfect, and fluoridate Angoon's water supply. a) Two (2) each 42-inch diameter verticle pressure

filters, maximum rate in duplex operation: 57 gpm @

3 gal./min. ft2; 76 gpm @ 4 gal./min. ft2. b) Chlorine saturator /-I-'jltJ d~/"n~~r-;, f'--c) Downflow fluoride saturKtor

3.2.3.2 Tank: Regulating, fire, and emergency storage is effected by a 100,000 gallon wood stave tank south of

town. With an inlet elevation of 158 feet and a bottom elevation of 142 feet most of the town experiences 30 psi 'to 35 psi water pressures.

3.2.3.3 Distribution System: The current distribution system is as shown in Figure 4. Total length of mains is approximately 7,500 feet.

- 24 -

TEST I'OINT NO. 4

H .... nil' UNE--_

-0- 'rI0I LIHI---..J

FLEX MOS.

SUalllDt«D

C~~l /~.= I

. t>J ~~ POW!,. LUD ~i ~ CONN!CTlO\ • Jih

LI'" DISCONTlNU! ! TO 'ORM IIOTIOIII

'/S,-..-----TtST P'OINT NO. I

lEACH PUM'

TUT POINT IIQ.I

lI!cnflEII

POWEll LUI

I

-

.. .. -

~ ,J ,

-----------

;

; i : : 1\ !, I .

...

~ARCO BALL JOINT (BB 31020-48-11 N) ~600 ROTATION - 150 ANGULAR FLEX i TEl

90· ELBOWS-BOTH SIDES OF BALL JOINT

ASKET ON BALL JOINT IS OF RESSURE MOLDED ASBESTOS

rOM POSITIO N.

FIGURE 3A

ANGOON WATER DISTRIBUTION SYSTEM

-_..--2;-___ _

".

CHA rNAM STRAIT

. I

_--1OQ.00{j fOALt./lOO "1"[. ,T()jIAQE lMoIll

LEGENO =

." 0. t

." ..... c:.

NOTE -

" ,

•

a

SECTION IV SYSTEM IMPROVEMENTS

4.1 Projected Design Flows: Previous studies conducted by this and other offices indicate that an appropriate design average daily damand for Angoon is on the order of 75 gpcd, quite common for most small villages throughout Southeast.

Various flow rates, other than average, must also be considered in the design of a water system since water consumption does not occur on a uniform basis. These rates are summarized below, both on a per capita and projected demand rate basis.

Water Demand

Average Daily Demand Maximum Daily Demand Peak Hourly Demand Fire Flow

(I) Ratio

1.0 2.0 4.5

(1) To average daily demand

RATES (2) Per Capita Design Flow

75 gpcd 42 gpm 150 gpcd 84 gpm

189 gpm 500 gpm(3)

(2) Based on a projected population of 800 (3) For two (2) hours

The fire flow rate was derived from the minimum amount of water recognized benefical for fire suppression by the Insurance Services Office of Alaska. This office has the delegated authority of setting insurance rates, which in turn are predicated on available fire protection facilities.

Note that the tabulated rates consider only domestic and existing commercial uses. At this time there are no heavy industrial users in Angoon. Any industrial/commercial facility proposed for the community must be evaluated with respect to water demand and existing/proposed supplies at that time. Also, increased flows may have a pronounced -~ffect on the operation of the existing sewage treatment plant. ,Should average daily wastewater flows exceed 60,000 gpd, improvements to the

- 28 -

, I

f

II

1

..

•

•

existing plant may well be required. Such improvements would represent a real cost which must be considered if significant expansion of the water system is proposed.

4.2 Reservoir: 4.2.1 Requirements: Demand rates used in determining required reservoir

storage are generally based on maximum daily demand. At 84 gpm this is equivalent to 44.2 million-gallons/year, or 135 acre ft./year. Using this demand rate and knowing the runoff characteristics for a particular watershed, it is possible to determine storage requirements for a reservoir within that watershed. Such an evaluation follows for the basins under consideration.

4.2.2 Alternatives: 4.2.2.1 Existing Basin:

A. Runoff/Required storage: Unfortunately, it was not 1lOSsible to directly estimate runoff for the stromgren Creek watershed. While there is good precipitation data for Angoon (Figure 5), there are no gaging stations on Stromgren Creek. However, the U.S. Department of Agriculture has developed relationships between preCipitation and runoff for ungaged streams in Tongass National Forest by correlating known data for this area (Reference 1). The bottom solid curve in Figure 6 represents mean annual runoff per square mile of watershed as established by the Department of Agriculture and has been plotted as a function of mean annual recorded precipitation in Angoon (note that the drainage -basin is some 300 feet higher than the Angoon recording station). The top solid line is a best fit through actual runoff data for the closest gage station, Hasselborg Creek, which is 16 miles NE of Angoon. The data for this basin (35,840 acres, mean elevation over 1,000 feet) has also been plotted as

-29-\ . \

i I

.. .' ........

-CJ) w ::I: U ,z :::::;

z 0

ti t:: Q. U W 0:: Q.

-1 <t ::> z z <t

ANGOON PRECIPITATION DATA

~O

MEAN 4

~ PERIOD OF RECORD-HASSELSORG ~ CREEK DISCHARGE

20

10 • .. ANNUAL TOTALS )t---~ ~ YEAR MOVING AVERAGE

O~~~~~~~~-+~~~-+~~~-+~j-.~~~~~~~~~~

52 56 60 64

YEAR

68 72 76 80

41.9"

.

fiGURE D

• •

z (/) ct CD

W

6.0

5.0

~ 4.0

Ci u..a:: LLc

~~ :Jw a:...J 3.0 -':liE ~ci Z(/) Za:: c:(l&J

n. ...,: 2.0 it ~ g o

, -

---,~---"'--,--~----" --~.~---~

LOCAL RUNOFF ENVELOPE

®

~ ;,'

ACTUAL HASSELBORG CREEK DATA! REGRESSION COEFFICENT OF DETERMINATION (r2) =.73

~-- SYNTH£TIC DATA BASED ON RE-GRESSION ANALYSIS 2 FROM WATER RESOURCES ATLAS (5)

o ~--------~--------r---------+---------~--------4r--------~ 30 35 40 45

ANNUAL RECORDED PRECIPITATION (INCHES) NAT. WEATHER STA. INDEX 0310-ANGOON

I. BASED ON CALENDER YEARS 1952 -1967.

50

2. REGRESSION EQUATION 11*(MEAN ANNUAL FLOW - TONOASS NATIONAL FOREST) n=4'8, r2::J.99

* Q:: .0312 pl.l3 AI.03

'ft¥"".

FIOURE 8

I

i !

:1

t

a function of Angoon precipitation. A water balance for this basin clearly indicates that precipitation levels are much greater in the Hasselborg Creek area than in Angoon. It follows then, that the envelope described by the two regression lines represents the range of runoff levels to be expected in this general area as a function of recorded precipitation.

Using stereo pairs of infrared photos (scale: I-inch = 1,085') for the stromgren Creek watershed area, the total drainage basin area was determined

to be 280 acres (Figure 7). Figure 8 is a mass plot of basin runoff for the lowest precipitation period on record (1954-1957). Runoff was determined using the calculated drainage basin area, recorded monthly Angoon precipitation data, and the Department of Agriculture mean annual runoff regreSSion equation. Using the "mean amual" equation with monthly precipitation data and then scaling the flow up by a factor of 12 tends to moderately underestimate TUnoff, as snowmelt is discounted and evapotranspir­ation is overestimated to a certain degree. The analysis is, then, conservative. Also shown on Figure 8 are several demand lines. The required storage capacity of a reservoir may be determined by measuring the maximum departure from the appropriate demand line drawn tangent to the mass curve and points on the mass curve itself which are forward of the tangent point. As discussed earlier, a demand of 135 acre ft./yr. seems reasonable for Angoon through the year 2000. Based on the maximum

departure (1955), storage should be on the order of 15 acre-feet. When a reservoir is impounded, evaporative losses from the reservoir surface must be considered, increaSing the required storage.

-32-

rt-.. ,TCH!U. (J LAKE

fEET

• . .

t: i a . ...I

W ... II: ! ~ II: 0 i5 0 >

II: ;:. W II) ... w

0 II: Z ... ~ w • ~

RUNOFF MASS PLOT

EXISTING RESERVOIR

I •. O~~---------------r-----------------.r-----------------~----------------~

14.0

12.0

10.0

4.0

• It.

DEMAND UN" ACU-n:' ....

.... ,,, lASED DN IIEGlinSION muATICHI 0- tcsz ,JJJ ~.QJlll

WHU,. ,.- alUM MONTHLY ANOOON ,."".,..fATlDN A-UO AC"EI

However, runoff also increases as a function of reservoir area because transpiration losses decrease. For this basin, the gains due to decreased transpiration probably exceed the losses due to evaporation, suggesting again that this analysis is in many respects, conservative. Based on the above discussion, a design reservoir storage volume of 15 acre ft. (4.9 million-gallons) has been selected.

The maximum yield of the watershed is a function of 'storage also. Assuming it is feasible to build a dam large enough to impound the required storage, the basin becomes limiting when tangent demand lines no longer intersect the mass curve. For the low flow period in Figure 8, this limit is 375 acre ft./year or 230 gpm. Note that this would require a 75 acre-feet reservoir. As will be shown later (Figure 10), a dam with a spillway elevation of 279.5 feet at the existing site would be needed to effect this storage (24 million-gallons).

B. Existing Storage: The contour information in Figure 9 was developed from the existing reservoir as-built plans and stadia data (154 points) collected in January 1981. From these data then, reservoir storage/area curves were derived for the existing dam site with and without the two (2) upstream beaver dams (Figure 10). For the given spillway elevation of 271.6 feet the total volume of water stored is 6.0 million-gallons, distributed between the three (3) basins as summarized in Figure 11. Note that without the beaver dams the existing dam would only impound some 1.1 million-gallons.

- 35 -

. --~ - - -- .. ~-- .. --="

This is, however, 500,000 gallons higher than previous estimates of basin A capacity made by this office. Based on the selected design reservoir volume of 4.9 million gallons, it is clear that the beavers make the difference between adequate and inadequate storage. Without the beaver dams, consideration should be given to raising the free water surface of the existing reservoir to an elevation of approximately 274.5 feet. This would require either a new dam or a 3 foot to 4 foot extension to the existing structure.

Note that mass curves may also be used to determine the maximum expected yield for a given reservoir capacity. Tangents to the curve in Figure 8 such that the maximum departure just equals the existing capacity, i.e., 6.0 million-gallons (18.4 acre-feet) will have a slope equal to the maximum yield. In this case, yield is limited to 200 acre ft./yr. or approximately 120 gpm.

- 36 -

17.0 .... - .. lUI ... .... _. 11&0

I?t.D

t I . !

! I I f

I

- •• U J.' ... .. , ..

FLlVATIOH - $TORAGE/AREA CURVES

lXlSTING DAII SIT[

OHGOO!!. ALASKA

,..,.-ACIIU

...

~ , .

U

DIJIIIII~~ _______________

n. • .. .. .... ... " .. ... •• • • •• ... .wu. -10' IM.I.DtII

... --....

-... .... . ..

EXISTING RESEVOIR PROFILE

NTS

BASIN MILLION GALLONS

A \.I

B .5 --_. --

C 4.4

TOTAL 6.0

"GURE II

c. Quality: Chemical analyses performed to date on raw stromgren Creek/reservoir water indicate that it is typical of Southeast surface water. While generally meeting all of the National primary and secondary drinking water standards, it is fairly agressive and there are occasions when certain maximum contaminant levels are exceeded, specifically turbidity (primary standard) and color (secondary standard). In light of the isolated watershed and the treatment provided, this source should pose no health hazard to the residents of Angoon. It is expected that color will continue to be an aesthetic problem, especially if this reservoir is enlarged without first removing the existing organic overburden.

4.2.2.2 Lake McCarroll: As a part of the overall review of local water resources on Kootznahoo Head, a preliminary investigation of the large lake some 1.5 miles northeast of the existing reservoir was conducted in the fall of 1980. Should additional water be required, this lake, referred to as Lake McCarroll, may well be the best alternative for development. Summarized below and in Section 4.4 are our findings to date. A. Quantity:

1) Runoff/Required Storage: Although photo interpretation of the Lake McCarroll drainage

basin was not accomplished for this study, it is clear from USGS topographic and PHS field information that this basin is at least 960 ~cres in area (Figure 12). Using the runoff relationships developed earlier, and assuming

an area of 960 acres, results in the mass plot shown in Figure 13. At the maximum "potential" departure point, the 135 acre ft./year demand line is nearly equal in slope to the mass curve. This indicates that little or no storage is required on this basin.

- 40 -

l I

" t •

t .1

• t I

t.

SCALE: I": I MILE

LAKE McCARROLL WATERSHED

FIGURE 12

Ii: i . 9 ... ... « ~ li «

3 0 > II:

~, ~, ... ... 1/1 ... ... 0 a:: Z t; ~ II: z

" .1

!

RUNOFF MASS PLOT

LAKE McCARROLL

I~O'~------------------r------------------r------------------~--------------~~

4~O

40.0

•. 0

50.

20.0

ISoO

10.0

6.0

N 1t'4

MAXIMUM POTEN1IAL D'PAltTUItl

"'1

DEMAND LINES ACRE- f'T/YII

It,. JAN

(II lASED ON ItEIIIIESSION EQUATION O. [,051 Z pLiS ~'01:l1Z WHE"E' ,.. MEAN MONTHLY ANGOON ,.ItECI,.ITAl1ON

A ... HO AC"ES

,

From this same curve it can be determined that the maximum yield of the basin is 1,250 acre ft./year or 775 gpm.

2) Existing Storage: Soundings of the lake using simple raft/line/weight techniques revealed a maximum depth of 45 feet. From 13 data points the volume has been estimated at 160 million gallons (490 acre ft.). The maximum yield of the reservoir then, is indicated by the dashed line in Figure 13. However, as this line has a greater slope than the basin limiting line, the maximum "practical" reservoir yield is also 775 gpm.

3. Quality: Analysis of a sample collected in August 1980 suggests that this source is

comparable to the existing water supply. While color and turbidity were not evaluated, it is

anticipated that these parameters may be somewhat better compared to the existing reservoir due to the greater depth of Lake McCarroll.

-4.2.2.3 Other: A. Thayer Creek: It has been suggested at times, that

Thayer Creek, which is some 5 miles northeast of the existing dam, be developed as a water supply and/or a hydropower site. However, no serious consideration was given to this alternative in this report due to the excessive transmission line xequirements anticipated.

- 43 -

>, ".

CIIE!,IICAL & GEOLOGICAL LABORATORIES OF ALAS.KA, INC.

P.O. BOX 4·1276 Anchorage, Alaska 99509

TELEPHONE (£107)-279-4014 ANCHORAGE INDUSTRIAL CENTER 274·3364 5633 B Street

ANALYTICAL REPORT

:"CSTOMER Alaska Area Native Health Service SAMPLE LOCATION' . Angoon, Alaska I FOR LAB USE ONLY

~ COLLECTED 8-28-80 TIME COLLECTED: 1520 Hrs. RECVD .BY NJ, LAB /I 4879-2

LED BY J.~~cC3rrq11 SOURCE Lake lv'<£armll DATE RECEIVED 9-2-80 . ~EMAR KS See Attacheg Tag '. !.

DATE COMPLETED· 9-6-80 .. ,

DATE REPORTED 9-8-80 , , .. ".

SIGNEDfl-c.J~ ,;f~A t =

.!!!9.Ll .. ', ~ .... ; .. ''' ... [1~g ,S il ver ___ --=-<0=..:.:.,::0:.::,5 ___ [] P , Phosphorous __ --..,.;.<0,;,.;.;..;;0.;..5__ []Cyan ide, ________ _

LJ;.J ,Al umi num ___ ,;;.O-=..::, 11=-__ []Pb, Lead ____ '_' ':_<0_'_0_5__ []Sul fa te ____ O_. 3 ___ _ ." •. ~ .... ,J ••• '. '.

I I .i,Arsenic ___ ......;<:.:,.O.:...:,l=--__ []Pt,Platinum ____ <O_·0_5 __ []Phenol ________ _

[]Au,GQld _____ <.;;.;:0;..:,.~05=---__ []Sb.Antimony-'_-'_" '_<0_._1_0_' _ []Total Dissolved ___ 3_5 __ _ '. "' .. Solids

.'

i ; . .ioron _____ <.;;.;:0;..:,,~05=-__ []Se,Selenium <0.1 []Total Volati1e _____ _ ~ Solids

r'~a,Barium----<...;:..:0= • ...:::.05:::..--- []Si ,Sil icon ' .. ' "'0.95 []Suspended _______ _ Sol ids

Liui ,Bismuth <0.05 []Sn,Tin ' -'<0~05 []Vo1atil e Sus-_____ _

J r i,Calcium ___ ---""8=.3~ __ []Sr,Strontium.-·· .. · "~-'·<0.05 , pended Solids 25 []Hardness as ______ _

,

[JCd , Cadmi um ___ ......;<O~. 0=-='1"--__ []Ti, Ti ta n i urn <0. OS CaC03

[]A"I kal inity as ____ 4_1 __

1, ),Cobalt <0,05 []W,Tungsten <0,05 . CaC03 []----------

. ,

Tlrr, Chromi um ___ <.....;.;0:;..;,,~05=--__ []V, V an ad i um ____ <O_, 0_5 __ []------------

lj'"tJ ,Copper ____ <=o,.;:.., 0;;;.;;5~ __ []Zn ,Zi nc _____ <_o_. 0_5 __ []---...,....----------

r e,Iron _____ 0_._33 ___ []Zr,Zirconium ___ <_0_.0_5 __ []----------, * * * * * *

I]Hg,~'ercury----<=O....;;."l----- []Arnmonia ________ []mmhos Conductivity--56_--Nitrogen-N

1 • ,Potassium ___ ......:1!:.:,...:::.0 ___ []Kjedahl []pH Units ______ 6._7 __ Nitrogen-N

flM9,r~agnesium 0,71 []Nitrate-N []Turbidity NTU _____ _

i,)·ltl_Manganese ___ <o---,-._0_5 __ []Nitrite-N. []Color Units ______ _

,'" ),Molybdenum-----'<,.;:..0.;..,.;;0....;;.,5-- []Phosphorus []T .Col i form/lOOml ____ _ (Ortho) -p

~JNa,Sodium 1.2 []Chloride ____ -.:1=---__ [] __________ _

. i ,tlicke 1 ____ <;;,.:;0..:.,,0;;.,;5:....-__ [JF1 uor ide [] __________ _

4.3 Dam:

B. Mitchell Lake: A preliminary investigation of Mitchell Lake (1 mile northwest of existing dam) was conducted for this study. Using a surveying altimeter (single instrument method), its elevation was determined to be 385 feet, approximately 100

feet higher than the existing reservoir. Analysis of a lake water sample produced the attached results. Study of this lake was discontinued when it became evident that Lake McCarroll was a more viable alternative.

c. Favorite Bay: Although Favorite Bay is not located on Kootznahoo Head, it is mentioned here because others (principally the Angoon Community Association, Alaska Power Authority, and Tryck, Nyman, Hayes) are presently investigating the potential for a combined hydroelectric, commercial fish hatchery, and water supply project in this area (Reference 3, 4, and 5). An analysis of their findings and recommendations should be compared to these data for Kootznahoo Head when/if water source improvement decisions are made.

4.3.1 Requirements: Based on an out year population of 800, any dam on the Stromgren Creek basin designed to meet the projected reservior requirement must be capable of impounding at least 4.9 million gallons of water. Reservior requirements in the McCarroll basin are minimal. Sufficient head should be available to provide flow to the storage tank in town (158 feet HWL) at a rate equal to the maximum daily demand (84 gpm in this case). Note that the required head will vary with length and type of transmission line employed as well as head losses experienced through the water treatment plant.

- 4S -

....... ..--< , e __

CIIE1'rlICAL & GEOLOGICAL LABORATORIES OF ALASKA, ItIC. P.o. BOX 4·1276

Anchorage. Alaska 99509 TELEPHONE (9071·279-4014 ANCHORAGE INDUSTRIAL CENTER

274·3364 5633 B Street

ANALYTICAL REPORT

USTOMER Alaska Area Native Health Service SPJ.IPLE LOCATION: r-..:.:An==n.....::.;Ala=s=k=a_~:---___ _ FOR LAB USE ONLY

DATE COLLECTED B-29-80 TIME COLLECTED:' 1345:Jrs. RECVD. BY . AG LAB # 4879-1 I

_ AMPLED BY· J.~carrol1 SOURCE Mitchell Lake • DATE RECE IVED_9_-_2-_B"-0 ____ _

'-.Et~ARKS __ se_e_A_tt_a_ch_e_d_Ta_g.:<..._ ____________ _ DATE COMPLETED.;...· _9-_6_-_S0 ____ _

---------------------:---- DATE REPORTEO'--9_-_S-_8_0 ___ _

----------~-------SIGNED~cl-:,~~~2~ mg/l --- . .!!!9Ll

]Ag .Si1 ver <0.05 ___________ []P,Phosphorous <0.05 []Cyanide~ _______ _

(]A1,A1uminum <0.05 ___ ~~ __ [] Pb ,Lead ____ '_· -.,;<O~. 0:...=5__ []Su lfa te ___ ---=O~. 6~ __ _ .' .:' . .

· []As ,Arsenic <OJ ___ :>0.l.I.0....1.-___ []Pt,P1atinum <0 as []Pheno1 ________ _

1 []Au ,Gold <0.05 ____ ~~ ___ []Sb,Antimcny <0.10· []Tota1 Disso1ved_5 ..... 3 ___ _ Solids

[JB,Boron <0.05 ____ ~~'-__ []Se,Selenium <0,1 []Tota1 Vo1ati1e _____ _ , Solids I [JBa ,Barium <0.05 __________ []Si ,Sil icon 0.75 []Suspended _______ _

Sol ids , []Bi ,Bi smuth <0.05 ___ -.;.;:;.,;;.....;;..::.. ___ [JSn. Ti n <0. 05 []Vo1atile Sus-_____ _

! []Ca ,Cal cium 15 ___ -=-____ []Sr,Strontium. <0.05 pended Solids

[]Hardness as ____ 4.;;;..3 __ _

[JCd ,Cadmi um <0.01 ___ ~~'-__ []Ti,Titan;um <0.05 CaCo,

[]Al kalinity as __ =66=--__ _

(JCo,Coba1 t <0.05 ___ --.::.:~=--__ []~1,Tun9sten <0.05 CaC03

[]----------

I (]Cr,Chromium <0.05 __ -"'=-=-> ____ []V,Vanadium <0.05 []---------­

[J---------­[]----------

[]Cu,Copper <0.05 ___ ~~~ __ []Zn,Zinc <0,05

I []Fe, Iron 0.14 ____ --"-'-=-:. ___ []Zr, Z i rca n i urn <0. as * * * * * *

[]Hg,Mercury <0.1 ___ ~ .......... ___ []Ammonia ________ []mmhos Conductivity 96

[]K,Potassium <1.0 Nitrogen-N

__ ~~ ___ []Kjedahl []pH Units 6,8

• []Mg,Magnesium 1.2 Nitrogen-N

__ --=..:..:::.-___ []Nitrate-N (]Turbidity NTU _____ _

<0.05 []Mn ,t'\anganese __ --.::.:~_=__ __ []Nitrite-N. []Co1or Units _____ _

, [Jf10 ,Ho lybdenum <0.05 __ ~o...loL.ooI ___ []Phosphorus []T .Co1 i form/10tml--__ _

[]~h, S'Jd i urn 1.4 ( Ck-tho)-P ______ ......... ___ []Ch loride ______ 1"""---__ [] _________ _

Ni Ni ke <0.05 uoride fl ___ _

4.3.2 Alternatives: 4.3.2.1 Existing Basin:

A. Impoundment - With the beaver dams intact, the existing dam and reservior are adequate. Without the additional storage provided by the beavers, this dam should be raised 3 to 4 feet or replaced. Raising of the dam may be accomplished either by extending the existing log crib or by constructing a flash board along the crest. Figures 14 and 15 are cross sections of the existing site and an alternative selected during field studies. Although rock is quite prevalent in these areas, field mapping of the bedrock profile is recommended before final decisions are made with respect to these alternatives.

The existing dam has an estimated 100 gpm leak along the toe. This leak has been steady since the dam was completed in 1969, but it is unclear if water is infiltrating the rock core along the entire upstream face (falling to the base before exiting at the toe), or if the flow line is directly from heel to toe along the base. This loss of water can become critical during periods of low runoff and an attempt should be made to identify/repair the leak if this dam is to remain in service for any sigificant length of time.

B. Head - Total minimum static head of the existing system is approximately 102 feet (bottom of reservoir intake to HWL of tank). None of the proposed modifications to the dam on this basin will Significantly change available static head.

290

~ W I.L 280

I z 0

!i > L&J -J w 270

260

150+00 100+00

fR~FILE

ct. EXISTING DAM

STROMGREN CREEK ANGOON, ALASKA (1981} .

i

50+00 00+00

DISTANCE-FEET

' ..

..

50+00 100+00 150tOO

FIGURE 14

290

ti lL.w

2 . 80 I

Z o ~ > w Li:f 270

260

150+00 100+00

PROFILE

~ ALTERNATE DAM SITE

STROMGREN CREEK ANGOON, ALASKA {I9Bn .

50 ... 00 00+00

DISTANCE - FEET

50+00

NOTE: SEE FIGURE 9 FOR SECTION LOCATION

100+00 150+00

1

j j

1 I , ,] ,

FIGURE I~

4.3.2.2 Lake MCCarroll: A. Impoundment - As storage is more than adquate, the

major consideration in developing this body as a reservior would be the design of a reliable intake structure. Lake McCarroll is impounded in part by a beaver dam on the southeast side. Overflow from this dam flows into an unnamed stream and then to Kootznahoo Inlet. If transmission line routing were to follow this stream bed, it appears from initial field observations that outlet piping could be laid either through or over (siphon) the dam.

B. ~ - Altimeter data for Lake MCCarroll indicated an elevation of 286 feet at the water surface. Development would result then, in essentially the same static head conditions as at the the existing reservior.

4.4 Transmission Line: 4.4.1 Requirements: The transmission line should be able to deliver the

design maximum daily demand, i.e., 84 gpm. Assuming a minimum static head of 102 feet for both reserviors being evaluated, this flow rate can be achieved with a variety of pipeline designs within certain total system headloss constraints. Summarized below are maximum equivalent PVC pipe lengths which will deliver 90 gpm, given the existing static head conditions.

Reference Pipe (C=140)

4 ... inch PVC 6-inch PVC

90 GPM Flow Criteria Static Head 102 Feet

Maximum Equivalent System Length (E.L. in feet)

-50-

19,000 136,880

4.4.2 Alternatives: 4.4.2.1 Existing Basin: The existing transmission line is

capable of delivering only 70 gpm (i.e., 4-inch PVC E.L. greater than 19,000 ft.) (Reference 7) to the treatment plant when the marine portion is in good repair. However, gasket failures in the Barco joints and corrosion of the steel sections along the beach are a recurring problem and, at times, losses to the inlet have been as high as 40 gpm. In addition, this 990 foot run of 2.3 inch 1.0. pipe has an equivalent 4-inch PVC length of approximately 3,000 feet. The submarine line is then, the major limitation in the existing system. Redesign of the joints and increasing pipe diameter to 4 or 6 inches will be the single most effective step in achieving the design flow. Options which should be evaluated in detail include:

New Crossing Location: Investigate channel bottom seaward of existing site for slopes allowing longer xuns of straight pipe wlo ball jOints.

New Design

1. Welded XX Steel with barco joints with synthetic rubber gaskets.

2. Ductile Iron with bolted usiflex joints. 3. Ductile Iron with boltless usiflex joints. 4. Anchored high density polyethylene pipe. S. High density polyethylene pipe inside ductile

iron with usiflex joints. 6. High density polyethylene pipe inside alternate

armoring jackets.

Depending on redesign of this section, other land portions of the transmission line mayor may not need to be upgraded to 4-inch or 6-inch diameter. Note also that at some point, capacities will become such that the

- SI -

booster pumps on the beach and in the water treatment plant can be eliminated. The data below are the best available information with respect to system head losses. Unfortunately, sufficient data was not available to evaluate treatment plant losses and such an analysis was beyond the scope of this study.

Assumed 4" PVC (C = 140) C value Length (ft) Eguivalent length

4" wood stave 4" PVC

100 140

300 560 3,492 3,492

3" sch. 40 steel 120 934 1,242 3" sch. 40 XX steel Barco joints & elbows 3" sch. 40 steel

120

120

990 1,317 1,590

1,077 1,432 4" PVC 140 740 740 Treatment plant ? 4" 0.1. 120 2,030 2,700

4.4.2.2 Lake McCarroll Developing Lake McCarroll would require significant additional transmission line. As shown in figure 16, a line could either be buried along the outlet stream bed and then along the beach (11,800 ft.), or over land to the existing basin (3,600 ft.). field observations and photo interpretation indicate that there is a ridge on the southwest side of the lake which may preclude an overland siphon design. Preliminary cost estimates to design and construct a new transmission line and intake structure are given in Section V.

4.5 Appurtenances: 4.5.1 Treatment Plant - The only modifications to the existing treatment

plant which should be considered are the reduction of system head losses through piping/filter redesign. The upper limit of the two filters now in use is approximately 76 gpm (@ 4 gpm/ft.2) i.e., an additional filter may be required to achieve 84 gpm. This may or may not be economically feasible depending on the redesign of the transmission line. Consideration should be given to these specific system losses in conjunction with transmission line design.

- 52 -

T

KOOTZNAHOO HEAD

CONTOUR MAP

Taken from

U.S.G.S. SITKA (C-2) QUADRANGLE

FIGURE 16 ~ .' ~ .~.

~ .

4.5.2 Storage Tank: Distribution system storage aids in supplying peak demands; and is thus used to attain maximum economy in the sizing of transmission lines and treatment facilities.

Peak demands which are normally supplied from a storage reservoir connected to the distribution system are as follows:

Regulating Storage: Where transmission and treatment facilities aresized to provide flow rates compatible with the maximum daily demand, regulating storage is normally furnished on the basis of additional flow rate required to service the maximum hourly demand. This peak is normally taken as 20% of the amount of water required to supply the community for 24 hours at the maximum daily demand rate. Based on a maximum daily demand of 84 gpm, the required Iegulating storage for Angoon is 24,000 gallons.

Fire Storage: The amount of fire storage necessary is dependent on the amount of water necessary to provide a specified fire flow over a specified period of time. As previously discussed, this value is 500 gpm for 2 hours or 60,000 gallons storage.

Emergency Storage: The volume of emergency storage to be provided within a distribution system is normally based on the reliability of water delivery from the source, in conjunction with economic considerations. In the absence of overriding criteria, one commonly accepted practice is to provide sufficient storage to service the maximum daily demand over one 24 hour period; 121,000 gallons in this case. Normally this is sufficient to allow emergency repair of treatment or pumping facilities if such is required. Note that in Angoon, water delivery is dependent on a submarine pipeline across Kootznahoo Inlet. Repair of this line could well require a period of several weeks. However, provision of adequate storage for such a contingency is not economically feasible.

- S4 -

In light of the above discussion, and considering that the existing tank has a 100,000 gallon capacity, adding an additional 80,000 gallons of storage would be optional.

Note too, that there is a small leak (5 gpm) in the existing tank which should be repaired.

4.5.3 Distribution System: Based on the projected design flows it is clear that fire demand will govern any rehabilitation of the existing distribution system. Assuming the most distant point in the main to be 3,000 to 4,000 feet from the tank, under 60 feet of head, initial calculations for ductile i~on pipe indicate that 8-inch diameter pipe would be optimal. Six-inch pipe could handle flows on the order of 400 to 425 gpm.

An additional consideration with respect to upgrading the distribution system is the some 2,600 feet of existing asbestos cement (AC) main along Chatham and Kootznahoo roads. AC pipe was installed because of its low cost, ease of handling, good hydraulic properties, and excellent resistance to external corrosion. However, it is a brittle material and cannot withstand point or beam loads well, a property which has resulted in numerous pipe failures in Angoon.

- 55 -

· SECTION V COST ESTIMATES FOR ALTERNATIVES

ITEM UNIT COST

Design New Beach and Submarine Line:

Field Reconnaissance Work (diving) $2, O~~/day Engineering $60/hour

SUBTOTAL Overhead/Profit 1St;

TOTAL (Rounded to Nearest Thousand)

Detailed Hydraulic Anal~sis of Entire Transmission Line:

Travel $500/trip Engineering $60/hour

SUBTOTAL Overhead/Pro fit 1St;

TOTAL (Rounded to Nearest Thousand)

Construct New Beach and Submarine Line: (Assume crossing location remains the same.)

Mobilization/Demobilization Pipeline Beach Pipeline Submarine Pipeline

SUBTOTAL, Direct Cost Contingencies

TOTAL, Direct Cost Overhead Profit

$30,000 LS $30/LF $lOO/LF

15%

15t;

TOTAL COST (Rounded to Nearest Thousand)

Repair Leak in Existing Dam:

One job @ $50 1000

Repair Leak in Water Tank:

One job G $10,000

- 56 -

QUANTITY

5 days 2 man months

2 trips 2 man weeks

2,040 1,000

COST

$ 10,000 19 1200

$ 29,200 $ 41380

$ 34,000

$ 1,000 41800

$ 5,800 870

~ 71000

$ 40,000 61,200

100,000

$201,200 30,180

$231,380 34,707

$266,000

COST ESTIMATES FOR RECOMMENDED ALTERNATIVES (Cont.)

ITEM UNIT COST QUANTITY COST

UQgrade Land Based Portions of Transmission Line:

Mobilization/Demobilization $70,000 LS $ 70,000 Access $50,000 LS 50,000 Pipeline $35 LF 7,580 265 z300

SUBTOTAL, Direct Costs $385,300 Contingencies 10% 38 z530

TOTAL, Direct Costs $423,830 Engineering/Overhead/Profit 25% $105 z960

TOTAL COST (Rounded to Nearest Thousand) $530.000

Install Gaging Station on Stromgren or McCarroll Creek:

One job ~ $25.000

UQgrade Distribution S~stem to 8-inch 01:

Mobilization/Demobilization $30,000 LS $ 30,000 Pipeline $35 LF 7,500 262,500 Hydrants $2,000 each 10 20 z000

SUBTOTAL, Direct Costs $312,500 Contingencies 10% 31 z250

TOTAL, Direct Costs $343,750 Engineering/Overhead/Profit 25% 85 z940

TOTAL COST (Rounded to Nearest Thousand) $430.000

Construct Additional 80 z000-Gallon Storage Tank:

Mobilization/Demobilization 20,000 LS $ 20,000 storage Tank $.75/Gal. 80,000 60 z000

SUBTOTAL, Direct Costs $ 80,000 Contingencies 10% 8z000

TOTAL, Direct Costs $ 88,000 Engineering/OverheadIProfit 25% 22 z 000

TOTAL COST (Rounded to Nearest Thousand) ~llQ.QOO

- 57 -

COST ESTIMATES FOR RECOMMENDED ALTERNATIVES (Cont.)

ITEM UNIT COST QUANTITY COST

Reduce Head Losses Through Water Treatment Plant:

Mobilization/Demobilization Treatment Plant Addition New Sand Filter Piping Rehabilitation

SUBTOTAL, Direct Cost Contingencies

TOTAL, Direct Costs Engineering/Overhead/Profit

20,000 LS $40/Ft.2 400 $7,000 each 1 $50,000 LS

10%

25%

TOTAL COST (Rounded to Nearest Thousand)

lli!!!. Mobilization/

Demobilization Intake structure Access Clearing Pipeline

Subtotal Direct Cost

Contingencies

Total Direct Cost

Engineering/Over-

Unit Cost

$70,000 LS $100/LF $130,000 LS $4,OOO/AC $50/LF**

10%

head/Profit 25~

Land Line* Quantity Cost

400 LF"

1.33 AC 3,600 LF"

$ 70,000 40,000

130,000 5,300

180,000

$425,300 42,530

$467,830

Total Cost (Rounded to Nearest Thousand)

$116,960

$585,000

$ 20,000 16,000 7,000

50,000

$ 93,000 9,300

$102,300 25,515

$128,000

Streambed/Beach Quantity

400 LF

4.20 AC 11,400 LF

Cost

$ 70,000 40,000

130,000 16,800

570,000

$ 826,800 $ 82 z680

$ 909,480

$ 227,370

$1,137,000

NOTE: In addition to these costs the marine line improvements already addressed would have to be undertaken. *Assuming NO pump station required.

**Includes rock excavation

- 58 -

SECTION VI DISCUSSION OF ALTERNATIVES

The table below summarizes the data developed in this report for the two water sources under consideration. Recall that the design reservoir yield for a population of 800 (little or no industrial water requirements) is approximately 84 gpm i.e., maximum daily demand. The required storage based on this demand rate was determined to be 4.9 million gallons.

COMPARISON OF WATER SOURCE ALTERNATIVES

Basin Dam Reservoir Trans. Total Yield Head Cost Storage Yield Quality Cost Line Cost Cost

Existing 230 100 $50,000 6 mil. 120. good $0 $837,000 $887,000 Source gpm ft. gal. gpm

Lake 775 McCarroll gpm

100 ft.

$0 160 mil. 775 gal. gpm

good $55,000 $1;367,000* $1,422,000 $1,919,000** $1,974,000

* Land line design .* Streambed/beach design

As the head and water quality considerations are comparable for both sources, and given that the existing reservoir storage/yield is sufficient to meet the design values, there is little basis for abandoning the existing reservoir. The improvements to the transmission line and dam which should be undertaken have an estimated total cost of $887,000. The two transmission alternatives from Lake McCarroll have been estimated at $1,422,000 and $1,974,000 including the recommended work on the marine sections Of the existing line. Even if the land line design is shown to be feasible, an additional $535,000 in capital costs will be incurred to develope this source. In the short term then, the recommended improvements to the storage tank, distribution system, and treatment plant would seem a better use of any funds available.

Based on the above data, the prioritized recommendations outlined in the beginning of this report are made.

- 59 -

SECTION VII REFERENCES

1. U.S. Department of Agriculture, Forest Service - Region 10, "Water Resources Atlas", Juneau, Alaska, April 1979.

2. Norton Corrosion limited, "Installation and Operating Instructions for City of Angoon, Alaska, Water Supply, Final Report", C-2078 Woodinville, Washington, March 1970.

3. Tryck, Nyman, Hayes, "Angoon Hydropower; Preliminary Reconnaissance Report", Anchorage, Alaska, November 1980.

4. Tryck, Nyman, Hayes, "Angoon Hatchery Concepts", Anchorage, Alaska, September 1980.

5. International Engineering Company, "Angoon Tidal Power and Comparative Analysis", Anchorage, Alaska, February 1981.

6. U.S.PHS, "Final Report, Alaska Native Sanitation Facilities for Angoon, Alaska, Project No. AN-63-339APW, -68-680, -70-690", Anchorage, Alaska, September 1971.

7. CH2M-Hill, "Water and Sewerage Systems, City of Angoon", Anchorage, Alaska, December 1972.

8. Bureau of Indian Affairs, "Angoon, Its History, Population, and Economy", Billings, Montana, June 1975.

- 60 -

APPENDIX A

..

J ,

1 j

1 , , I

) I

I

) )

'I

J I

I I I

-~~;-'-·~ ______ '_M_·~(._+~* ______ ._ . ~~_~ ___ ._t ____________________________ '~I __ ' ________________ '"''

--------

REPORT ON KOOTZNAHOO INLET

AT ANGOON, ALASKA

)"OR ADMINISTRATIVE USE ONLY

lJater Resources Division ~ted states Geological SUrvey

Juneau" Ala.ska (March" 1965)

Prepared by Charles W. Boning" Hydraulic Engineer David A. Sommers" Geologist

'\ .. ----~--------~------.. ------.. ~----~~ ... --... ---------------------

..

CONTENTS

Introduction------------------------------------------

Procedure--------- .-----------------------------------

GeoloSic Description of Channel-----------------------

Cross sections----------------------------------------

Velocity Observations---------------------------------

Conclusions-------------------------------------------

Page 1

1

2

2

4

5

i" 2 "' .

Figure l.

2.

3· 4.

5·

6.

bn nO

FIGURES

Location map--------------~---------------

Cross section A---------------------------

Cross section l---------------------------

Cross section 2---------------------------

Cross section 3---------------------------Cross section 4---------------------------

,

page 6

7

8

9

10

11

-

I ~

I :

.. '

•

. , 4' '.

. -..... --

REPORT ON KOOTZNAHOO INLET

AT ANGOON, ALASKA -' ~ .. :~.

DTRODUCTION

The site of this investigation is located in Kootznahoo Inlet near

the village of Angoon, Alaska on the west side of Admiralty Island, 58

miles south ot Juneau, and 42 mile s northwest of Sitka. The U. S. Publi c

Health Service requested the Geological Survey to obtain cross sections

of the inlet, magnitudes of the bottom current velocities at points of

probable scour" and description and samples of the channel bottom. These

data vill aid the design and installation ot a fresh water pipeline from

a source on Turn Point near Stillwater Anchorage across Kootznahoo Inlet

to Angoon.

PROCEDURE

Initial crossings numbered 1 to 4 in figure 1" were made at random

locations with a recording fathometer in the viCinity ot Village Rock in

the inlet. Visual inspection ot these sections \.;rere made by the authors

and by Public Health Service engineers who assisted the investigation, to

select the best location for the proposed pipeline. The tina1 cross section,

designated cross section A in figure 1 was then obtained. No horizontal

cont~ol was maintained during any of the crossings, although Public Health

Service engineers have subsequently made a transit survey ot the selected

cross section location.

Upon selection of the most suitable cross section for the pipeline,

atte!!1pts were made to collect bottom samples on this crossing. At times

~r maximum current as published by the U. s. Coast and Geodetic Survey"

velocities were taken in close proximity to the bottom at various pOints

across the channel •

.,.

.---

•

), C· pi '>tt# 1. _

GEOLOGIC DESCRIPTION OF Cl~L

The channel bottom is believed to consist or the same type of bed-

rock that exists at Angoon and on Village Rock. This bedrock consists or

inter-bedded, thin-bedded to thick-bedded, light to medium gray, crystal­

line marble and calc-silicate schist. The bedrock is complexly folded and

faulted, and shows well-developed shear zones. The general strike or the

rock units ranges rrom N 40· w to N 10· W and the dip averages 60· to 80·

to the NE. Thus, Village Rock represents the extension, along strike, of

some of the more resistant rock units that are exposed in the village of

• Angoon. The underwater ridge which extends northward from Village Rock

tovard Kootznahoo Head, is obviously made up of these same units. The

deep "trench, picked ,up on the fathometer, just to the east of this ridge,

mTJ:y be merely an easily eroded unit in the bedrock, but more likely it is

the manifestation of a large fault which presumably trends NNW-SSE through

this clla:rmel.

Bepeated attempts to obtain bottom samples of the channel were unsuc-

cessfUl and the soundings recorded by the fathometer indicated a very rough

IIlld hard surface. These findings indicate that the channel bottom has

~Obably been scoured clean of detrital particles, except for those that

may have been secured in some of the many irregularities in the surface •

CROSS SECTIONS

!he da:ta 'for the cross sections vere obtained at morn1ng low tides

. on Karch 16 and 17. The lov tide elevations on these dates were 0.3 feet

and -1.0 'feet respectively. Thus the vater surface elevations of the

-2-

• /

::s- ' rn b ;e bd ...... 'iw' * tt,·W"'. "S)"'_*"5 p .... ' .. rifcO _~

•

: ..... - " .~ , ....

cross sections in fiGures 2 to 6 ore at approximate mean sea level.

Horizontal distances were approximated from field notes and from map

scales.

The cross section selected as most suitable for the pipeline is shown

as the d.o.shcd line in figure 1, and plotted in figure 2. This cross sec-

tion utilizes the shallow portion of the channel between the ridge ex-

tending from Village Rock to the shore near Angoon, is far enough from

Village Rock to minimize the effect of the ridge, and crosses the main

channel where the deep trench has a greater width than in cross sections

1 and 2. By changing the direction of the crossing in the main channel,

the gradient of the pipeline on the steep sides of the trench can be

reduced. The location of this bend is approximately at the end of the

ridge extending north from Village Rock.

Cross section 1, shown as figure 3, lies directly across the channel

'on the inlet side of Village Rock. From Angoon to Village Rock, the bottom

c~nfiguration could. not be defined because of large amounts of kelp in ..

this area although approximate depths were obtained. From Village Rock

to Turn Point the trench previously mentioned is quite narrOW' with very

steep walls. Visual observation of the tidal flovs indicated extremely

high velocities in this area, which was the primary reason this crossing

did not appear feasible.

Cross section 2, figure 4, lies on the northwest side of Village

Rock. The portion of this cross section between Angoon and Village Rock

is shallow and fairly rough, but does not contain any large crevices.

The trench in the main channel has steep sides, but the velocities in

-3-

..:.~, "

, ';tn • .,' •

•

this area do not nppear as great as in cross section 1.

Cross section 3, figure 5, contains the trench in the main channel

and a deep hole in the portion of the section near Angoon. This cross

section was not considered the best crossing because of the deep hole,

although the fathometer chart indicated a widening of the trench in the

mo.1n channel.

Cross section 4, figure 6, lies approximately 800 feet toward Chatham

strait from Village Rock, and is in considerably deeper water than the

other cross sections although the "fathometer did not indicate the deep

hole that vas found in cross section 3 near the Angoon shore. From dis-

cussion with Public Health Service engineers, this cross section vas given

less consideration because of greater depths and the greater distances of

the cross section ends from the fresh water source and fram Angoon. How-

ever l if the velocities "in the selected cross section are greater than the

pipeline can be made to withstand l cross section 4 may be the most feasible

one regardless of the decreased accessibility, increased pipe length, "and

greater depths.

VELOCITY OBSERVATIONS

Velocities in the channel on the selected cross section were. obtained

approximately at the times of maximum tidal current as published by the

u. S. Coast and Geodetic Survey. Flood velocities on March 16 were taken

at apprOXimately 1120 between a low tide of 0.3 feet and a high tide of

16.8 feet. Flood velocities on March 17 were obtained at approximately

1200 between a low tide of -1.0 feet and a high tide of 17.1 feet. Ebb

velocities were obtained at approximately 1720 March 17 between a high

tide of 17.1 feet and a low tide of -2.7 feet.

,

, "

•

Velocitie~ were measured in the main flow channel between Village

Rock and Turn Point as it was evident that' this ~las where the strongest

current existed. The measured velocities and their approximate locations

are plotted as point velocities in figure 2. Mw:imum velocities of approx­

imat·~ly 6 feet per second in close proximity to the bottom occur along the

steep banks of the trench. No lesser velocities should be considered in

the pipeline design. Of the yelocities observed, the ebb currents averaged

approximately 1 foot per second stronger than the flood currents at equiv­

alent depths.

CONCWSIONS

~. The channel bottom consists of bedrock with no overlying detritus.

2. The bottom is extremely irregular with a deep trench in the main

channel.

3. Maximum velocities near the bottom have approximate magnitudes of

6 feet per second.

4. If the above velocities are greater than allowable for anchoring

the pipeline, the best cross section will be in the viCinity of cross

section 4 .

-5-

"-

3

...,(

.. :'!:'(' Tl:ll.'· .. ··, '~'! ::.,.,." .. , ';'::!; 'fI, ':, ,,'"

-. "-It.,.; 1.:..",- ~

i

I i

, I

1 1 j ,

.., ... -"-' ~ ....... ~~ .... ~ .-.- ... -.... _-. ",

.. ........ _ .. -r"------__ "":""' ___ . --IOIU----lIIIlIlalr::aelllll:jltaliP;:;;rwDril"'Ir.:::::1.::MC;:;:.:::;'L:J:,;:::: ::::, :::::::::::=%:::::$'±::Y~'.::=-

r

I -I j

-; • ..1

.' •• • 11

--*"--

I

I L

1 I

l

....... I

'3. . :.. t.. ~ I','; . ~I t.....

---.- ._---I· I

--.-...:.

J .!!&9 c .W _ 9&: , .. r

'·&'4:= "':~i.AiiIl'*t4#:

'~l

-·1 I : --1 ' .... , I~ '::) i l ;'-q

, --....

\ .- \

• ,-- r -.~--"'l'~~'------"""-""""'----

..... , :.~:"·i:":::·":+:£::·:·:··"· I \~

I

~ , I !

APPENDIX B .-.f

'"

, \

,

I " .. i_ -! i" I

1 -~-:+t-' :',: -i- .': ! '. I : ,M_._; I: :.I'-------,.~~+-'-I--\

I : I ' I, : "'1--, r-:--t "-~ -t-" I ; I ,I : i

"j' -~+- I--~ -: +~--'-------; f---+------I; ----'-+--;--t--. I : j i ~ ---+ - -- -- --- ~---

I ":;- J -,-. "r Ph' ",./1. 'D(/4" , '-'! : ' '

"~-.l---i--.!-.:- _.}~ ,_-::"S,_J . I ,

~ I I' , ,

4_

1-+,+-"j "I ~ -:-h- '-.~ 1'/' ", '_Ti~---\--'~~:-~; .ro-;; -1-r'.';-

: ! , i ,T: :

i . ..;,..-- _._+- -

-O--t---.~ - -- - .~-

."" ~ " 'J". .1'( ,~ ~'M .:" u~,.

" t, " 1 1..

lL}J.~:J~~-........... -

.. . .. -

~--......... -, ~ .-..­-., • .,~ M'

, : st· ., , "~ss:. /'ln~ of -,. , : I!~I<

.-~.- --- --"T-~'·- ---, ! 3-1/ n; : :

"~ , , ,

u, ttp •• IM!'NT Of 1U.!.~'" i: :..a!~ l .lo.'~ ~ (. "IAL'!'ot ~~I'''o(j

",.,\.Of c ..... :- ....... '*.-..

£.N4rr f''''''''''-.J p~ -L.

¥.L~:~:~-+;.~;1...tt~ t _-_ .. O .... CI ,.~ _ ... .. _­,-. ' ..

-4

!

.l

! I '-t---t ____ +_,--!!---, ! I ..

I

-_._. __ .- . , I

I " 1

-t-: t· -~ -+----"-"""'-1 1 :

!

i-r"~+

I ~ - t,

I , : n' "Of( ... ~.,!, ' . -r/.- .- ,,~ r-, , - r-1·1 : '

--t~1 __ J-~ -- .. ,' , ! , ,

., -...;., -t- -,', -:-'''''1' , I

I

,.

.~

" "..

, ..

APPENDIX C

. -.----------:---~~---------

Anoo.e

8a~~\ . . ,I . '.' . , .,.... 0' -. ,

I , . , '.'

/ I I

~ I

PIPE LINE

f-co ~,

o .. 5 CIIannll Edge ~

..... ~,>. ' ... : 0) .'.

"'"age Rock ' • •

n--==r==~~==1 1 :~

I

i, ;1

AOMIRAUTY j;

ISLAND i:

:! I,

II ii'

t • o «01't.

PROFILE OF CROSSING _. !f

o 2CO 400 ft,

' ...... , ......

I' -==--==:lI_'O (:

PROPOSED PIPELINE CROSSING IN KOOTZNAHOO INLET BETWEEN ANGOON a TURNPOINT

BY: U.S. PU61.IC HEALTH SERVICE OFFICE OF ENVIRONMENTAL HEALTH DATE: OCTOBER I, 1968

..... ' ..... . . r \' , ~.

,

d I'

)

1

... -.

.. ~ r',

" .

\ \

.. , .

,'"

",,- -

"I

May

FRCtI. J&Jiles A. Crn:::, A661stan~, Sa:litar:r Er.gtneer

SL'nJECT: Angoor. Crossing Telephone conversation w:th U.S. ripe, Seattle, ~~. Ron Si~on, Sales Representative

I received a call from Mr. Ron S~:on concerning the flexible JOint piFe their can;any !r.anufactures. F.~ gaye the follo .... ing price quotes:

6" ID Boltless Flexi~le Joint Pipe ..nth 1/16" grout lining, (I}Jctile Iron) 0.52" Wall thicYJless. 18 ft. sections,

4" ID Boltless fle~ible Joint pire .... ith l/l~grout lining, (Ductile Iron) 0.52 ~all thickness. 18 ft. sections.

The high costs of th~ p:pe are r.8inly due to the machining costs during manufacture. I d:~c~ssed the corrosion protection .... ith him, in particular a vater line in salt ~ater. He stated several instances .... here cast iron has provided ser· ... i::e for' over 60 years in o'.ltfa.lls, and one w-ater line in salt vate!" at Seattle .... hi~h has lasted 20 years. He did not knc",; if this line had eathotic protection. He felt that the line mayor may not need protection.

Ioir. SiltO:'l s-:.sted ~hat the compa~1y .... ould need a 6o-day deli very date on their Ductile iron fl~xible jOint pipe.

We also discussed the pull-out force required to disjoint or structurally damage the boltless connector's. Be stated the connectors are designed to ~rovide tbe same strength as the pipe section for pull-out so that it would be possible to fail in the pipe before a JOint .... ould. fail.

He wIll send a more detailed price break down to

JAC:f'ln

,

o~ChOrage office.

l.::~ J. i;-James A. Crum Field Er.g1:le~r

.,

;.#. '

\(

MEl-1ORJu·t1)al FOH ToiE RECORD lJ.ay ~2, 1968

FROM Jar::e3 A. Crwr., ':'ssis+.tlnt Sani tar:; En£ine~r

SUBJECT: Telephone conversotloc to Houston: Catholic Protection Sc:-vice, Mr. Jack Dav1.s

The Protection Agency stat~d that the ductil~ iron pipe will corrode 10 tr.e salt water, and vill need a sacrificial anode protection system. The best method would be to use zinc bracelets ~hich could be placed on the pipe during installation. The bracelets vould give the pipe a 40 year life.

Mr. Davis discussed the corrosion resistance of both cast iron and ductile iron with me. In particular he discussed the claims of It~ pipe manufacturers that the salt water environment will not have any effect on the metal. Mr. Davis stated if the pipe is to be used in a sewer outfall for low pressure use, it would require nO protection; but in high pressure lines-, there ~ill be failures. The iron actually rusts out of the metal leaving the carbon for strength. This would s~pport a buried outfall for many years, but vould result in failure for a line ldth high currents and hi~h pressures.

Mr. Davis said he would prepare his recommendations today, and send them to our office in Anchorage.

JAC:1'm

~~_ ti&­Zn:: ~A. Crwn Field Engineer

APPENDIX D

, .

'"

~.

;t Ii ..

.Ii

. !i ; I'

I

111

I I'i : I • I

II , I

I

II 1

II I

/I

i

I!

I I , :

t,

.... ,-,,0 ~ .• ______ _ --------. -- ._--

-FIELD TRIP RZPOf.'I'

. • JDJ:lCS A. Cruml Sr. Asst. Sanitary E:l£incer

, /' ;" '-; _. C ,.,

.1 'I

SUDJEC'r: Tr1p report to Angoon, Alaska, l-larch 22.;.231 1969

The following report 1s about a field trip to investiGate the bottom condl tiona in i(ootznahoo Inlet. Arter th~ ductile iron pipeline bids were reJected, it became appurcnt that we knov the exuct bottoD coni1tions in order to predict how a pipe system vi~h variable spaced JOints vould react in the tidal current. The ductile iron line vas to be laid in a flU" shape usin; e~~l sp~ccd joints. !r~re would be construction problc~s involy~d in tl:::.~i!lg the bend in the line in the deepest part of the ehaxmel, W'ld 1n1 tial h1G3 costs due to the increased line len::th. The channel relief ~p 1n~icates a tetter cross section near the turn of the proposed ductile iron ll~e. This trip w~s made to investigate this cross section in detail vith ~he intent of crossing the channel straight across vith the heavy subcurine pipe. (See sketch). This would result in a r.ore exact aliE~ent o~ the laying borse d~lng construction, and reduce the cost o£ the thick­vall Gut;:arine pipe. Th~ shore connections could then be !:lade v1 th a thin­walled plastic-coated steel pipe laid below the lov tide line.

SDturd~y, ~..:J.rch 22, 1962

I ltet vith E:.:b Beck, Ju."leeu Diving ASSOCiates, at noon; and ..... e ch!lrt.ered a plane to Angoon. ~e established the shore targets as sho_n on the a~tached d:::...:i~.. 1-:e the!]. place!! an. :mellor on exact line ... 1 th th:! ~gets in t:!:e deepest portion of the channel with an a~tached buoy. The anchor line vas. used by tbe diver to get to the bottOQ in the shortest acount of time, and to always return to the same point on the cross section.

fJ'be high slack tide (+14.0) vas at 4:48 p.m. (Juneau tides) vith a one hour correctio~ for Angoon. The diving cn tbe first day was to check the s~neral bottom conditions on the cross section. We felt that the second day could b~ spent vork1ng on any problem areas or to look. at speci:1'ic regions of the bottca. . . First drive - BlOY to turn 'Oo1nt shore - Start at 5:50 p.m. (10 minutes length)

The d1 ver vent dow. th3 buoy rope to 115 feet depth (depth ceter) and beaded JI..!le;net1c North, vbich is the magnetic bearing of the desired cross section. The £lat area exists at ll5 feet depth as indicated on the relief map. Tne diver encountered a +:1) ft. pi!lacle in the fl.at :::.rea just to the right o£ the cross section (See drawing). This is not shown on the relief ~p, due to it not showing on fathaceter depth-indicator used b,y the Geological Survey,.

The diver found the bottom toward the turn point shore quite different than indicated OIl the relief I:.:l.p. There vas a 20-25 ft. cllff rising off the bottoo. at a C-o° slope fro:n llO ft. depth to 85 :1't.. depth. After this ell!'! breaks, there is ~ short flat area (10· slopc)(Sce draving)1 and then another Ii: nlar elif: 20 ft. high at about Goo slope. The base rock in the area of these tva c11ffs is not extrc~ly rough.

• ._. __ rc

• o Above the cecond clitt there are scattered six ft. ~inus boulders. Further toward the shore, there are c~ller boulde~s (three ft. r.inus in d!~~eter) similar to vhat can be seen on the shore at lo~ tide. (See pictures) Tbe diver c~e up on the turn ¥Oi~t shore directly on line vith the ohore targets.

'!'he diver indicated that the nquad1c life on the botto:n ws quite ditferent 1'rom what he had found in the arca of village rock (Bob Beck aJ.so did the diving during the installation ot the hose in 1965). In the deep gorge there are cany large (su inch length) b:U-!l:lcles attached to the rocks, grassy-moss growths over the rocks, and four inches clnus s=ooth gravel on the bottom. These conditions did not exiGt in the vil13ge rock area vhere the rocks bad been scoured clean, and no gravel existed.

After the diver surfa.ced at the turn pOint shore, \7e returned to the buoy, and he again vent to the bottom.. He then took a r::agnetic south bearing, aDd beaded for the Angoon shore. Approxi~tely 20 ft. south of the ouoy be encountered a cliff vhich rose at 600 fro~ 115 ft. depth to 70 ft. depth (depth meter) (See drawinc;). The cliff bad a sharp break at lta crest, and the botto~ leveled out toward the Angoon shore. After the break at the crest, the bottom \.Tas very flat (gravel) -with a large amount ot aquadic gro~. He called it an "under vater pasture". The gravel deposi ts are about the Sm:le as exist on the turn point beach. The diver 1nd1cated that there would be no problec in gettiDfj 40 ft. pipe spsns to bear on the botto.:l in this aree. Uear the Angoon sho~ a.t 25 ft. deptb .. the slope rose abruptly at 60 0 to the surface es ,,-::.s indicated at cross­ae=t10n fc~ i~ the Geological Survey Report. Thi~ ~tee~ ~lO?e e~i3t~ all along the Angoon shore bet'loo-een the ohore target and the village theater.

In rev1eving the vork we had done on the first day, .. -e realized that the relief ~p vas in error. The five cross sectiOns used o~ the reliet map were never tritUlo"Ulated to establish their exact lOcation in the cr.,annel, &0 they were placed approx1.%:lntely on the map. Possibly by InOvi~ due vest ~ the cross section we ""ere ""~rldng on, the cross section indicated on X-cross section :io. 4 of the Geological Survey Report could be found. This 'WOUld remove the three cliffs ve found and provide us \lith the bottom condi tiona vere loo:.dng tor. This vas the approach we vere going to usc on the second day.

Sunday, V~rch 23, 1962

IDv slack tide ..a.8 at 11:08 a.m. Juneau. First dive at 12:05 p.t:1. 15 cinutes length. All bearin~s on C'.agnetic. Actual alack tide vas found to be 1 hr. m min. after the Juneau tide schedule.

The first dive vas made to find a cetter cross section tOW3rds Ch3tham Strait. The diver started at Anchor a:ld Buoy POint, and headed due vest along the crest ot the r1d;e. He felt that the ridce vould b~Gin to become les9 vcrticle as vcs indicated on the relief ~? rtt 40 feet vest fr~ the Anchor pOint, the cliff c~Led directicn and he~ded On a S.E. Bearinc;. hcst of this tip vas a rocky-gravel bott~ startIng at

t. !

t . I'

"

1,'

. ,.

.", . --

... '

. ~

I ....

..

. .

..

o -,- o 105 ft. depth. Change in vertical elope on a Bouth bear1n~ ao investigated vas '5 teet, and the general slope tended to ce 30° and continued to the flat portion of the c~~l to~d An~oon. The dlver th~n started on a North bearing to the turn polnt shore. Tide cau13ht hlo, and he had to surface out toward Chath~ Strait. Cr1tica.l cbannel velocities appear to be on the outgoing tide as found in our diving. This probably is due to the Jetting effect of the village rock area.

tJe returned to the Buoy and waited for the tide to slacken. Then the diver vent dow the buoy rope 8i;llin, and headed \rest f'rOl:l the Anchor. At 40 ft. out he turned north and t'ollOYCd the botten to the turn point shore. General visibillty vas approx1~tely ;I:) ft. at 105 ft. depth. TO...,..c1rdS the turn point short the s~ 25 ft. riGe d1d not exist 88 found on the first day. The general slope rose at approx1I:lately ;00 to the turn point shore. The bottom consisted of scattered 3 ft. diameter boulero, shale, and Oeach gravel.

On rising at the shore, the diver vas 45 tt. due west of the original beach target. The origiD:ll. markers ve:'e later pem.ancntly marked vi th red paint.

"e then returned to the buoy to try to photograph the bottom. The diver vent dow the buoy rope, end again headed due west to where the cliff' turns S. E. He then continued fUrther vest until he could determine that the cross chrumel (no clift's) \;'as at least 100 ft. vide. No photos vere taken due to a calfunction in the camer~ We then stoppcj for the day. The center buoy \laS left in place, and the shores .ere marked as indicated above. Later the end points were triangulated to check the accuracy of contract map.

tfhe check of all angles 'Were vithin one degree of what could be scaled at the drawing.

Left Angoon via charter at 5:00 p.m.

Ji\C:tm c. e . C~H j;.I.£)(~ ,.;Ji',.. .. rc. ~ .

James A. Crum Project Ene1neer

. :

. Ii',: ·I t . II 1)",,",_ ~)'1 rl~·.:::1~ .. ---_.- - ---- - - I I ____ ~ ---_.- - i ___ .1 __ -

-~---==-=_'I ___ '_-. --- .---- \ --- - \ ~---

, ro-1

t

;

1 ,--I I , I I ! -1--

~ ~ ~-i

[ -

~

, ~.

L 1

i ,.'

I .. ,

,- .

, ..

r . 1: ..

! -

'. ~ ..

• I . .0

<)

. 011 du-l4."c<,~ Cf,.~ ... A'" .... ~d~., IA.lClt ...

es~,:'".ft.~ - ",,_tic. d .... ~"'f I:" .. ;,J,'; .. S

. ___ .J _____ . ____ . _______ _

• A"14 4''' -p,,u.·I'~4- ~/"1

HtUCk 2.2.-2.3 ,~" . . :r ....... ~C. .... , V''''''''1 AS~,e)~14.J.e.S

/

I I

I

---.~-- -~- - -, ),. - .,-

.-. -- .. ,-

7

I /. -

\ --.... "-.--"- "- --- - --- --_._ .. , .

-J I

/

"/ .-­

/

._------_._-----

. , \

--'---f"

Ai'I~"'1 tl~eI."''''4~ "-

----I . --- --l-

J

,----_.j /'

1100 !-I-I...---.-------- ' ------ -f -/

1/ / /

/ /-:::: .. , ;i

I --1

-,

:d--.6 :

I I !

! G-C:- : : I

I ! I !c. -d-: I

I

I I

I I

I

I

__ ._. 4u~~,J

~~ ~O(/~J~ I L?~se;z ,.I::::.~;J ~/- 0' 10 • - 1'5° 5C-oP£

J

L6f)6£. ~.. ~~~A7G<:y .5~t:?~T1f'/ Sc.oo,€/....uc::? ~/~r - .LJt'(/~ /d::.~~~~ u:..~ ~~ r

;;:t.,. .1)~ ) .5o~£ &')vrc~/:s ..s ~.. ~c;...rf;

,.e~r..JGI/ /Jv"- 0 ~e:/ ~a?lO~ /." /1//Vv S bet::..

~CL- / ~~gc-.e- . :2-"­L!.1fc.., T£ V/.:;x:...o~.£. ~ 3C> 0

.x1't~sE. ~H-rrE A;,u~~£ ~TJ7

..

-.'

. :

APPENDIX E

•

"1

....... -.... - --_ .. -.

. j -

1

" .

"~' "". ~ ,. - ~

ALASKA AREA NATIVE HEALTH SE~VICES ANCHORAGE ,ALASKA

CATIIODIC PROTECTION DESIGN FOR

CITY 01:' ANGOON, ALASKA WATER SUPPLY

C-2025

NORTON CORROSION LIHITED Woodinville, Washington

October, 1969

. ' .'

·J

] -. l

J

'" 4

l .., .4 , i4

~.". ~

]

J -r

~ ..

SCOPE

CATHtlO H; prtijTEc.-i! OJ.! DESIGN FO:t

CITi 0:: M~GOON, t.t.ASI~.:4 tIATER SU:-'t'!...'1

. AngocmJiAlcska. The drS\of1ngs ~i1d te;chhic;;:1 d·3i:~; supplied 31'0 1n-

tenclad to give al1 tho necs~!ii:ori' inforlnat1on for

C-2025-1 sho~s th~ 1ccation aid sp~ci ng of tha ground bed~ cad,

anod~ must be in~tal1erj usiny tile lolire brackets (C-202!:i-2), E<:!cr.

header cab la. to the rE;cti fi e,"sl\i)iJld be stricii ght imd di i'.!Ct.

- --..-.,.--- ----

J .. .

l ~

~

l J ~ . .'

I

! 1

I

l i

J I

l :;

• :1 ]

1 :] .(

.-',

']

~ .'

~ ~ I~

::: .. . ~. .

'fh'" (ancXlcr'S. t:!raloli "9 e·2025-3 sh)u I ~ be. $P~ apprOl<": r.,e tt :.Y; /~ ~_. • •••• :-~l.·\! f', ~t~D III ~A"'.. -I;"~ S -- Co-" :'··<-I'·':'.,! 0"'..-:_:' 6 '...a l', -... ... ... 1 ... _...A tOo - "\ _" ~ 1~ .. "\~ ,.'._ 1 • 1_ ' .. ':r,,"~I'- :_ ............. ' .. g '-( ~ ..,.... w: .. ~

• i I

QSS~st in p(ac..it\g th.; snode6 nt'\dwire,t)1\ tha.bO't~~ Th~C.3bte..

i~Ji 11 be ~;jcr:!i(:d ilia ~. condvi t: Yrc1'il nr.>~;·c.;d~::d ~~ }'" the .. ~ roof:

, t c:- """..,t ~ ~ .... _ .... .1 •• ,

c-ko"'n 0 ... · '''r ." .. ,- r ,. - "0''''< ~ _.. , ,...". 't~ -.-1 .. "'.. t"'" - •. ' ",. If" ""!A., ..... I ........ ~ "U , ... ., rlJ ..... - .. ~"/f al~"l .·_ ..... 0 'i,;v ~,... .J' {.;:.l.~~ ,,--QJ,-IJ"', •

NeGATIVE. C O~CTION

FrY~ the r~ctifier

. . >,·:i; . . - ..... ,'" , ... ,. '"'n<'S l' L-l'", -."d '&'1' 1 "i ~ -i •.• ; · ... '1 .... j-.., :,;!..t~.; •• i ..... ") 1.I .... ..iA ;"'.~. :-.• 1" • • I C~I ~J. t..r ,_ i';: •

•. :,... ...... ~, c' . A c:. ~A .~~ t w' t.t:.v •• ,...,........

--- -. . -,.....: '. 0" _ .. :: il !,;v 4 fP. ~ ..... :.; JIg

\.;.:0, ",', ~I':-a:-) 1 ·r . - -{- ~. .

...

C ?o r.'·"5 ~ • . -., ~:>- , ,o::~tca

ab~ ti) ~ ffp",,~ e.Nt. ~ ~aD"J~\~ l\"r\e.) .s~e "'-u>2S-I) ~

Mo. 6 A~ cAD (e.: ;;;,-::.:; cs~.J ·j.1 ;~ ~l gmc:tu it, . SaMu Id. ~ i j'; 5 t ~ I 1 cd •

. _.'

-.--~.-----" ~---r1

.. -1 . I

l

3-1 J ]

J I J I r ]

I I i I I l

. ' .

~tGATIV~ eONNECTION (~~N1INUEO)

Thi ~ w'i (a wIll be. (;cmr~ted. to t~e 1/0 pc)~EiZ 1 eael Q.$ ~hovJ.' an

{ora~roa c.-'2D7.S"~ .It ~Q,lI'" ~ burled. ~r~1(i~~ let' ~. ~~~Ol~

1'he.n: a(4!--ft,ur -test poi r.t:; provi dc;:d. .'-:)~y ~~i".::: '(.'}I.:a.::=.:'i ~

each 4r.<:t ~ tht- sh ... 1rca. 11 nes!, as i n<1i c~tecl t;n C~,20?'5·· 1. TY/D ~

the~ poi nt~ arl'; t\,,") be iQcateJ j4.lst abov~ ~ h~{}h \O!otlter 1~~1)

\llitJe-re. t~ ehore lin~s co"nect to tna ~S6.s" "These points sooul&'

b&.~ir~ per Oia'JEil1g Gc.2052-~. Ona.~t" polnt' i~ located en Turn

C>oi nt Shore ilnd f 5 to be hooked up' pet Dnfwi rig C -2052-6. The 1 as t'

-t~.st' poi n tis 10:: i:1 ted on the s1;%9(.')on shor e and i s the same poi n t.

used. fer thE!' negat'j ve connect', on. Tl1i s. test fiG; Il't shvll i ti be wi red.

pef OraNi:;9 C~2025·5. At the two test points ceil i ir,g for a 1/0

.. i re "from the pi pet, thi s wi re haS been 1 ns ta j I ed and i..s now coi led

on the. be~ch.

~EUE R;}.t, HOTt:S

.1.. All \oIit·~ is to he i'r"!stal1ed undergi·ound in conduit to a

point even with a -4 foot tide Hne. ihe d;;pth to be 18 inches.

2.. At 1 connections must be \.1!ater tight and made per DI'a~-Iln~

C -2Q2S··H.

3. After inzt:al1ation a recognized Corrosioil Conti",1l1 CCHlp:.t!1'j

must p~j'forlll the start-up operatiOt'5. Thi,;; ",iIi inclIJdi! art cl'j~!rrt·

furni !;hl~ci_ -- - -- -.- - ., -----,..

___ ------------------,------------------.~,t~-M~f~~'~'.'&~,.,k~l~e __ '~j~~~drt~·£.-tt~*«~r~. __ ~1~b~-·.~~M£~"~:*;t~,*w-T~,:~:_6d~' __ '-._-, a .~ ....... *'IfIII!h b

J

~

l-

~ 64

:3', ,0' ,>-

If' . ~, 4

~ ~

1 1 1 ,-

.. ,.

4. DrU\~ings C··2025-1 thru C·1025.8 and the Sf 11 or ;'l~1~:~~iial

an) filcluJcd as r, p~H·t Oi-: th-j::.: !-.p!.;c1ficatior ..

Rl.C;vb/C .. 202S

t 1

'1

' . •• 0'

. ~, . . . .:. '. !.. '; .. .

. ': .i.,:</;:"; :rjiiF<Y-'.'

3' "

, .. !.

\ .;

'~. '. . . ',- !

.•... "1' ;'. '. .. •. " '.

" .' .. bra.de

.. '

' . . ::: .

'.1 • :., \.

SPLrc.E KlT--..--.......

/I ", ~ 4 Jt 4- X b Trt!4 ted Woodefl Pos r

3/ II 13' L' /4- . USI)'hcj

, . '. :. I

" . ... ,' " •• 1

'.

, " .

. . ~~: .. ... ; ..

J't:,"TEST LEAD --­~NO,GAW6 .7STRAJJD. C.p. CA.BLE

, . ~ (Q/dw~/J or Brd%e

W"""&S 1(J Fiee.

. . ."', . .,:: .. '

'.~.

'r .. • •• J •

'<'~::.'(~J:' ::;:;~:r1EsT po';~~r#i''7 IJ .,:~ . _ ~.' ~.' '. : ) ~) 7

.. :·X;':: ": ~ ... ~. ~;:;:;:::'.~ :. ',.<':. tesr P"/nt let"l'YIlttA.IE/()ck ":': . .:-f:-;:~.<:::·· . . . . ;. . ~:. ,. ..'. . ,',. I- ,', ... ... .

'.. .' VIir esC 0 hn ~c..t e d to Te.r m '11a./w;.fh· . ';" ';' "<::"-' .. ~ . . <~.;~ .... ?:: ".::~~~.~~r. f·.~~~.~.c:. tor tt£ ~::;'-:IO c>.~:F. ~ ,,~I . .~:

. ' ... ,'.: '.?:,:.:;;, i"?(:/)f,;;)/~ t,\l;"~/.~: ... ,:E. ' :'X'>: '·:;P?:.: · .. :::> ..... ,.···:·~.·r.~·.h ... ·.· .. :.-.. ~ Noie: ",:'

• • • ~ ",.' ~ ..... :.~ ••.•• ,. ..... ·'4~. "'.~ :. t.". ---:" ...... -~~ .. ' ,"

- .' .' ... :; ' .... ! .: "'f " •. ~~ ~>:.: ;':.:: :: ·Any Srtlak ;1'7 W/re :r17su /0 -lIon

:

-'." •• :'.';.:.~;~'.~.".".~~:'.~ ••• ' I .::,:'":~'.:;;~·:;.I.' >/" beRep~/rt':d w/I-;, :2 flQlf L(Jopeq' r ••.•• •••••• 3//1'-'1 I. ',., ... : . ~'. __ .. >'. . .::::, ::,:.:.~ .. .":~"~:··.i·: Loye rs o-f"/4 rviC/~ M~ IrI (lit. .5t:-(J'f~ 1, ":":'~' .... :: .. ~:~ ::. . .:' ; .. ~:.: .. : ... ;.:::-::' : E~~a.-Ir;col. Taf'c! ~. 56 ('I- E<:j,I.A4!

.r~·~;.;.:t~;·::·~,. '.: ;1-::';i·":'~~I·t:~.t"i .. ······ I····· .... -..:..-.- . -.-.---------. . : ,. ~ :',' .~.: ~ .~. 't-. r' ": , . '; .r ~ •. '~. J .1\ :" i J';.~ f. :.; (j: .. I: :' •

. '. . ..•. ~;~ .•• .',' .. : ," ...•.. 1 -~:t~··. . C.,!;~·ll!':'!~ .. ~ C():ln:)5InN ;~." ,- ...

, .... : ..... ;~~i '~.j: ~:-.'!' .. .I.:.. . .. ~;.~~~ ~'~ ,';'wC'r,o':"'/lr'~ '.AI,. ... ~.,~ •• " :,." " • o· •• "~ ", .-.-----.- • - ... ----

(". ~ .. "-.", ~ t . . ,-, . ' ... ~ ... ~ " ... ' • . .

. -. It' .' '-. I'~

... _-... --.,...----~..,.j

1 . .iJ. ________ ............ ____ .... !'-... ,.;;;··~:ne=il;M:lIioIfIitI_' 'IiS.".,l"iIIi'IoIII·,t"''1O_KP'::MI'liIIa tiliO''lOiIi'N'''' •• t1i1911OS4'i~>;::t.iIt·¥T"M'N"''':DIIIIMIIiIi'iIi;i··mllDl .... a:a;'Ml&I::rDt9ll11ol.!1mr:.ll--lIIUiIIl ... tlilo:)'t __ .... ,.~ltP?m:.~UllCiJI: .... ..,... __ .. --+ ... ,

J J I~-----I'---,-, .-, -'~I-------.... r.,...·--G-'X-4-,.,'(-(;-·-Tr-e-:/-:r .. -.:J-~-·,,-.::-a',,-., h~:- "'1

J

,.., w.,

r

,I / I I

I

,. \ ,.': .. "

9C1slc..::t .:ll1d No. 75. 4~ ~:m":QI C/.J-:-' or e'('i~d

.. Pipe Sfr,J;!~

•. G (,1/", ('on '-Iv'- t

•. p/p e Sf'" oJ P

_____ \ ~. i3v! h/'7 9

. S L..)I.,o

w

.,- :!>W/":<r!S - No.GAwG Sf',-an:tec:l - CQfPc:,r w.' n 6;·.) V:,Jt n·, j I~ S -'. aT .In

•

\V'~e:; (".:l"'·e<:fe:i 1.) i;.r..,~,'n;J1 w:r,., Sr4koh Connecror trr;.6-JD or E'I:..Iq/

"

i>AII)o' CrE.:Jk /" W,re ~"lJsu/~t/vn , T:> I:: t!. ~ i?f:al'" ~ <-i '-'';.'7-;' 2 11 a; ~ L ~~,: p e. d

L :l'fC:"! 0'" :;:;." l·/,..1.? I-rM, f ,"'" _~;;)1'::17 EI(!ctr,":q/ Tope N~ . .33 ()I'" E 'tu~/.

~) rv\",,~,_ ......... ".... .- \ :;:: 1:'

J A ~~ 6~ S F. :..; () !~ TO:, CONSULtl"C (0:'0510N fN:;'''';HIl

wo 0 C I N V I L If. WAS lot INC T 0 I~

CATHOOlC PKOTECTIOf'-J A ,..,InnF T F .<",T P()) N T __ _

•

7e", -2X60" 051 ~NO pe.S PLAcJ;D t3F-LOW I-Ow -Lew . Nee 1.,#oIS - 7 S t:7AIif.. ANODes

S1b4.F..t' VAlOJ>fL w~r£t. ~K

. ;' .. . ,' -~ .

. ,. ~

.. -•. ': .:.~ '. ; -.. . '.

POll/lOll. hlF..r'iE/C.

~~'CONDv'r . ~

No ~CALF-

As -BUlL, GENE~A~ AR~AN~~1~NT

CA"tHOO"C. YR..O'TF-C.'t"ION >}--'S'TEM

AN f::-o ON) ALA S I:.A

~~--------------~--~--~------~ .-\ _~ J

" ~

!i 1 1 II J l l l a ~

~

~

~ A

1 1 ~

f II

b risi .~ • •

.... -~~

ALASKA !'.REA l~f~TI'J~ HEALTH SER'i!C::S

INSTALLATION & OPERATING INSTRUClIONS fCR

CITY Of AN~OON~. ALASKA HP. iEP. ::;UPPLY

c- 2Q78

NORTON CORROSION LIMITED Woodinvil Ie. Washington

MARCH 1970

------------~'""T""',I

.' I

- ~ ,... ...... ~

J =l :r J .-

SCOPE

!l This report present!; th~ ",~s··builtU detniis an'-; operat~ng

g instructions for the Gath<>dic rl·cfi:{~ctfon System instal led on

the subrnerg:1ld water supply of Angel)n., Alasl<ll. The dr~\oJirl\]~:~ i:' •• 1(!

~ .. technical dat~ ~uppli~d a~e inte~ded to present the final cnn·

j ditions. T!~~ s~'stcm is un irr.presseG curr~mt :ype: consistln~~ of

J

1 taring cf the instalit::d system.

~ Th~ grcund b~d consists of twenty 2" x 601: Durichlor 51

anodes. lhese ~nodes are pl&ced just west of Village Rock,

3 in two peral1el lines with ten anodes in each line. Drawing No.

l G.·Z078-1 ~nOc.olS the location i:;;,d splicing of the instal1f~d groLmd

Lcd. 'f:le fi.1al insta1lat1on was moved approx.imately 200 fe~t

l v:est of th~ recoOliilend'3d location due to loca 1 wat~r condi tions.

J final observatiolls by the diver indicates that all of the anodes

are : n go:>d condi t i o.i..

) The rectifier used is a L.O volt, 50 amperes, oil·~irnroorsed~

I si1icon~ foot-mounted unit. Goodall, Model # COYSA.4·Q··50.D·1i30··

PQ. It is bolted to a concrete pad~ located per drawing C-2078-1.

r Present operating conditions are 3.5 vo1ts, 4.0 amperes.

r-

• 0 '1 til t

PAGE TWO

from tha rectifier to a test point, located about 60 feet

f.tn the end of the crossing lir.e, a No.6 AWG cable, enclosed ,

in a ~II conduit, ts installed. This wire is connected to the

l~O power lead and is the negative bond.

There are four test points provided. They are located at

each end of the shore lines, 8S indicated on drawing C~2078-l.

Two of these points are to be .located just above the high water

level, where the shore lines connect to the hoses. One test

point is located on Turn Point Shore and the last test po~nt 1s

located on the Angoon Shore and is the same point used for the

negative connection. These test points are numbered one to

four, starting with the Angoon end of th~ pipe system.

OPERATION AND MAINTENANCE

This system should be maintained properly to insure com­

p1ete protection for the water 11ne. The 011 cooled rectifier

has oper~ting instructfons g provided by the supplier. The

instructions should be strictly adhered to. Potential measure­

ments shou1d be taken at each of the four test points on a weekly

. \ baSis. The operating personnel has been given instructions on

\perfo~lng these tests. The pipe potential should be maintained

\between -.85 and -1.0 V. 1-f it varies from these values, the

1rocttffer should be adjusted accordtngly. An increase in the I rectifier will make the pipe potential become more negBtlve.

,-At.., ... :

J 1 -

l 1 l l l 1 1 ~

~ ~ ~

" .. ~

a :] ~ ~

:J J

.j

0'

After oper-ating the syst~~ for a period of one year, it I I I

should be checked by a Corrosion Engineer. We will write for

authorization to parform this check when it is due. If any

large change to the system tekcs place befoie thfs tfme, it

should be brought to the attention of Norton Corrosion limfted

inmediately.

Very truly yours,

RLC :vb/C -2078

··-·--m i .' .

--Wf , :. "

I ' ~" ,

~" ii4

"

~' ', ..... >:.

~ ,.' . ..\ ..... ... ". :.!. .' ... ., .. . . \.... .

··" ..... 4.,

~ ".' ~ ':.~!".

, II" ~.", .

rt· ' ~ : . . . ~ ..

.fl

(

. , ::.1,

.. -.,. ", . . .

.'

a(

. ,

'. ' .. ,J, ,.' ..... " "

, r " ~ ,

J. ., .

• '.1 , ' . • r ..

" , "

::-: .: . • ~ J .• -:t

-.; . ' . , ," '.-1 -._:. t"

. . ... .; "·4' •. ~ 0.,'.' .. ':~: .. .-;\. ",,':

. :.: .. ,.:: .. :" ::',~ ;··/:':t. ',- , ..

" ... ..: .. :.;..... .~ .. . : ............ I

..... ''';.~' ~ ... ":

~'. ~. .. ".. -. ' .. _" ~",I

. ".\

~'<, .~

.. ' . ~: ...... ~.

: . . ' .

,', ' .

~ ..

•• r .

.... . .. ~

·'1" • '. ~.

",

;_. ., " .'

.... , , i