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HomeMy WebLinkAboutBradley Dam Movement-Weir Flow-Instrument Report 2006Bryan Carey (7 S From:Jon Miyashiro UStMiyastivo @ferc.govlSent:Thursday,April 17,2008 1:09 PM To:Bryan Carey Cc:Leona Bolton;Edward Perez;Patrick Regan;Douglas D.Boyer Subject:Subject:P-8221 Bradley Lake Project,Acknowledgement of 2007 Instream Flow Certification Subject:P-8221 Bradley Lake Project,Acknowledgement of 2007 Instream Flow Certification Dear Mr.Carey: This is to acknowledge your December 10,2007 letter transmitting the 2007 Instream Flow Certification for the Bradley Lake Project, FERC No.8221. We have reviewed the submittal and noted that the minimum flow requirements for the period of October 1,2006 through September 30,2007 have been met.This e-mail message is being sent in lieu of an acknowledgement letter.If you have any questions,please call me at 503-552-2732. Sincerely, Jon K.Miyashiro,P.E. Federal Energy Regulatory Commission Office of Energy Projects Division of Dam Safety and Inspections Portland Regional Office 805 SW Broadway,Suite 550 Portland,OR 97205 Ph.(503)552-2732 FAX (503)552-2799 ALASKA 5)ENERGY AUTHORITY Bradley Lake Hydroelectric Project FERC No.8221-AK Penstock/Tunnel Drains Video Inspection Performed 07/19/05 FINAL REPORT June 12,2006 R&M Consultants,Inc. 9101 Vanguard Drive Anchorage,Alaska 99507 Tel:907-522-1707 T=3¢=[MIR&M CONSULTANTS,INC. ALASKA ENERGY AUTHORITY Bradley Lake Hydroelectric Project FERC No.8221-AK Penstock/Tunnel Drains Video Inspection Performed 07/19/05 FINAL REPORT June 12,2006 R&M Consultants,Inc. 9101 Vanguard Drive Anchorage,Alaska 99507 Tel:907-522-1707 PREFACE This report was prepared for the Alaska Energy Authority (AEA)by R&M Consultants, Inc.The report is based on the findings of a video camera inspection of the Bradley Lake Hydroelectric Project penstock/tunnel drains performed July 19,2005.Questions regarding this report should be directed to the undersigned at 907-522-1707. Permission for the use of this report by third parties shall be only with the explicit permission of AEA. R&M CONSULTANTS,INC. June 12,2006 ohn K.of Weacgex Table of Contents Section Title Page No. EMtrOductiion ............ccsscessssssseseecsecseescssteceecacesscessaensasesececsaeseseceseeecsecsseessseesacensesessseesaseessseessecessecs 1 Description of Tunnel Drains...............ccseccssscsssssessessenesceseseesessessensssessensensessseesceausaesaserssceetessensens 1 Prior Camera Inspections of Tunnel Drains ................:cccccssssssssessesceseescssenssseescsseeesasencsseaectensensens 3 2005 Video Camera Inspection of the Penstock/Tunnel Drains ................ccccssssceesetssccecenecscensensens 3 EqQuipMenth...........ccscsssssessscscesscsscsseessceeessessescensscessesessescsaceacscceseasessessssesseausneeescaesnessesseseseceaesnes 3 Equipment and Technique Test Details..............ccscssssssessssseceeceeceseecrscesscnconeneesaeseescesceaceneses 4 Inspection Site 0.0...cess sseccscssscecescssccessccesncssneesnesencesauecenesssaeesesenscesseessneseneessssetsnaeesneeresseeses 4 Details of Procedure for this Drain Inspection and Observations................:cscescsesesseeseeerseseseceenees 5 FAMingS .......scccccsscssssscsseccescssesscsesseessnessesssacensenececesasaceeesessaseateneseceaseaasaeeaeensesssaesensseeseecesseeseees 6 COnclUSIONS 0.......ccccessssecsecessecescssnsesscessensnensessesesseseasesseesesseedeacecsssanseceseesesarenseeeeserssseesteaeesesennees 7 Recommendations ............sccssssssssccsssceseessssessncsscseacenscensessesseseasseceessecsceseceesceveceseecasscnsvonsetacenseas 7 Attachments- Attachment A-1 through A-3 -Excerpts from 2001 Part 12D Inspection Report Attachment B-1 thru B-4 -2001 Drains Inspection Letter Report by Remy Williams,P.E. Attachment C -Power Tunnel/Penstock Liner Plans and Details,Sheets 1 thru 3 Attachment D -Photographs from Construction of the Penstock/Tunnel Liner Appendicies- Appendix 1 -Images from Video tapes of 2005,2001 and 1998 Drain inspections Appendix 2 -Calculation of Calcination Buildup. Bradley Lake Hydroelectric Project Penstock Tunnel Drains Video Inspection Performed 07/19/05 Introduction Recommendations from the 2001 Partl12D Independent Consultant inspection Report for the Bradley Lake Hydroelectric Project included a recommendation that a video camera inspection of the power tunnel and penstock drain lines (tunnel/penstock drains)be done in 2006 prior to the next scheduled Part 12D inspection and that the inspection be done to at least 500 feet into the drains. Prior video camera inspections were done in 1998 and 2001 but inspection equipment was able to penetrate the tunnel/penstock drains only 76 to 150 feet due to limitations on the equipment and resistance of the calcite build-up to pushing the camera through the pipe.It was indicated by the Independent Consultant that a greater penetration distance into the tunnel/penstock drains was needed to ascertain calcite build-up conditions in the tunnel/penstock drains. For further background on the tunnel/penstock drains video camera inspection matters,excerpts of relevant pages from the November 2001 Part 12D report are attached (Attachments A-1,thru A-3). Also,a copy of the letter report for the 2001 inspection is attached (Attachment B-1 thru B-4). At the request of AEA R&M Consultants,Inc.performed a video camera inspection of the Bradley Lake Hydroelectric Project tunnel/penstock drain system on July 19,2005.The inspection had two purposes directed specifically at the tunnel/penstock drains only;branch drains to the powerhouse clear water sump were not inspected: 1 To determine the extent of calcinations build-up in the drains since the 2001 camera inspection. 2.To determine if it would be possible to penetrate 500 feet or farther into the drains with the push-type video camera on an umbilical. Description of the Tunnel Drains The penstock tunnel is provided with four 4-inch steel pipe drains that are intended to drain water from the rock surrounding the penstock and power tunnel steel liners.Attachment C presents Plans and Details of the liner and drain installation and Attachment D contains construction photographs of the liner installation. Attachment C,Sheets 1 through 3,contains Figures 1 through 17 which are details of the tunnel and penstock steel liner and drain pipes drawn from project record drawings.Figure 1 is a Schematic Plan (paste-up of images from project record drawings)of the power tunnel steel liner and penstock steel liner and Figure 8 is a plan of the routing of the drain pipes at the penstock manifold area of the tunnel.Figures 2 and 3 and Figure 14 are sections cut along the tunnel and penstock liners at the upstream end and downstream end.Figures 4,5,and 6 show details of the drain line clean outs and rock drain taps and figure 7 shows the general assembly slip coupling used in the drain pipe installation. The 4-inch steel pipe drains are located at positions 60-degrees above and 40 degrees below thehorizontalcenterlineofthesteellinerintheconcrete-filled annulus between the steel liners and the Tunnel/Penstock Drain Inspection July 19,2005 Page 2 of 8 surrounding rock,see Figures 10,11,12 and 13 which are tunnel cross-sections showing the placement of the pipe drains progressing downstream and represent drain positions to the curved transition to the penstock/manifold tunnel liner.Figure 9 shows placement of the drain pipes in thepenstock/manifold section and it is noted that the pipes are shown on Figure 8 as being routed to analignmentalongthebackwallofthetunnelexcavationafterthecurve.Figure 14 shows the arrangement of the penstock linerin the manifold section behind the powerhouse and also shows the approximate location of the branch drain tees along the tunnel drains.Figure 15 shows the designed arrangement of the drains where they daylight in the Adit but this is not a correct detail as the drains are actually arranged in a 4-spot configuration with flange markings indicating drains 1 and 4 are above drains 2 and 3.However,the identity of the drain outlets in the Adit need to be confirmed by back-flushing through the drains in the Powerhouse.Figure 17 shows the purported arrangement of the drain pipes along the back wall of the penstock manifold section of the tunnel.Figure 16 shows the general arrangement and routing of the branch drains that connect the tunnel drains to the clear water sump in the powerhouse.Note that powerhouse east wall outlets of drains 1 and 2 are apparently located at the North end of the powerhouse and of drains 3 and 4 at the South end. The tunnel and penstock pipe drains run from Station 31+60 at the upstream end of the power tunnel steel liner and terminate at about Station 1+40 near the ellipsoidal closure head on the downstream end of the steel penstock manifold locatedin the Adit near the North end of the powerhouse.As noted above,Figure 15 shows the general arrangement of the drains at the Aditaccordingtotherecorddrawings.The total length of each drainis approximately 3,020 feet,295feetofwhichisalongthepenstockmanifoldand2,724 feet of whichis along the steel tunnel liner. The branch tees for diversion of drain water through 4-inch branch drains to the clear water sump are indicated on the drawings as being installed in the drain lines between 76 and 90 feet from the Adit (approximately tunnel stations 2+60 and 2+23),see Figures 14 and 16. The upstream end of each of the drains (power tunnel station 31+60 more or less)is provided with steel,square head,threaded pipe plug tack welded to the terminal fitting on the drain;see Figures 2 and 4.The plug is indicated on the drawings as being exposed in the tunnel concrete liner. The drain pipes are also provided with intermediate 4-inch cleanout fittings as illustrated by Figure 6.According to project drawings,these cleanouts are located at Stations 7+00,12+20,17+40, 22+20,and 27+00.Each cleanout comprises a 4-inch standard tee in the drain line with a threaded clean-out plug in the side branch of the tee under a stainless steel cover plate welded to the tunnel steel liner.To access the drain lines via the cleanouts,the cover plate would need to be removed by grinding or flame cutting away the welds to gain access to the threaded plugs.The slip coupling assembly typically used in installing the drains with the tunnel liner sections is illustrated in Figure 7. Drain taps into the surrounding bedrock comprise 1.5-inch drain holes drilled through the tunnel liner,drain pipe and annulus concrete to 12 inches into the rock to allow the groundwater in the rock to drain into the 4-inch drain pipe;See Figure 5.These drain holes are at 10 feet on centers in all drains from Station 31460 to Station 27+00 and at 20 feet on centers from Station 27+00 to Station 19+00.There are apparently no drain taps drilled into the rock structure downstream from about Station 19+00. Tunnel/Penstock Drain Inspxction July 19,2005 Page 3 of 8 Prior Camera Inspections of Tunnel Drains - Video camera inspections of the penstock tunnel liner drains were performed 8/31/98 thru 9/02/98 and again on 10/02/01.A copy of the report for 2001 is included as Attachment B-1 through B-4. Each of those inspections used push-type video cameras on an umbilical cable and each of those inspections included the branch drains from the penstock tunnel drains to the powerhouse.Access to the branch drains was through drain pipe outlets in the East (back)wall of the power house at the Elevation 5.0 level and through drains day-lighting in the Clearwater sump. The video tape of the camera inspection done 8/31/98 through 9/2/98 was reviewed and it was noted the camera was able to penetrate the penstock/tunnel drains up to about 150 feet.The limited penetration was due to limitations of the equipment and resistance of the calcite build-up to pushing the camera through the pipe beyond the 150-foot point.Camera inspection of the branch drains was generally limited by the bends just below the connection point to the penstock/tunnel drains. Images from the video tape of the 1998 inspection are included in Appendix 1. A review of the videotape of the camera inspection done 10/02/2001 showed that the camera was able to penetrate the drains only 76 to 150 feet,again due to limitations of the equipment and resistance of the calcite build-up to pushing the camera through the pipe.Also,camera inspection of the branch drains was limited by the bends just below the connection point to the penstock/tunnel drains.Images from the video tape of the 2005 tunnel drain and branch drain inspection are included in Appendix 1. Comparing the results of the 1998 and 2001 inspections showed that calcite build-up upstream from the most downstream branch drain tees is about the same for these two inspections.See Appendix 1 for images taken from the videotapes of these two inspections. 2005 Video Camera Inspection of the Penstock Manifold /Tunnel Drains- The 2005 video camera inspection was conducted on July 19,2005 using a SeeSnake pipe inspection video camera;this was the same video inspection equipment used in the 2001 inspection. The camera and operator were provided by American Marine,Anchorage and the equipment is described following. Equipment - The SeeSnake iis manufactured by Rigid tools and comprises a video recorder,video monitor,power-control unit,distance counter,lighting control and a video camera on a 325-foot power and data cableeich--y umbilical designed to be manually pushed into pipes. The camera is essentially a static camera with no pan or tilt capability.The camera is equipped with LED lights housed around the camera lens in the head of the camera body.The umbilical is stored in a shell-type reel that is provided with a counter indicating the distance the camera has been pushed into the pipe. Prior to the 2005 inspection,the video tape from the 10/02/01 video camera inspection was reviewed and a Tunnel/Penstock Drain Inspection July 19,2005 Page 4 of 8 strategy developed for extending the ability of the SeeSnake to penetrate into the drain.It was thought that if the friction and mechanical obstruction presented by the calcite build-ups were mitigated the camera should be able to be pushed into the drains to the full length of the umbilical. The approach showing the most promise and that would be most economical for the purpose was determined to be installing a low friction conductor casing for the camera that could also bridge past mechanical obstructions posed by the branch drain fittings.Accordingly PVC electrical conduit was added to the equipment list. Equipment and Technique Test Details - It was determined that the video inspection camera could pass successfully through a 1.5-inch conduit.PVC electrical conduit with bell and spigot ends was selected as the conductor because of toughness,low friction factor and convenient length sections (10 feet).A live test of technique and equipment was done by pushing the camera through the conductor at the American Marine facilities in Anchorage.In this test 300 lineal feet of 1.5-inch PVC electrical conduit was assembled (without solvent gluing)and looped around the American Marine yard.The camera was inserted in the conductor and pushed through from one end to the other without difficulty.The conclusion from the test was that the strategy would work and it was determined to proceed with the inspection.'hhgy'ummni"nroyi”pervertTn",>ro«¥i]wate.,hala14(ETIPUSIT TEST SET UP;NOTE SITELL REEL FOR CAMERA UMBILICAL A total of 300 lineal feet of PVC electrical conduit was purchased to serve as the conductor conduit for camera inspections with the 325-foot umbilical and an additional 200 lineal feet was purchased to allow performing a conductor conduit push test to 500 feet into the drains to determine the feasibility of supporting a camera with a 500-foot umbilical .1.5-INCH PVC CONDUIT TEST LOOP END All equipment and materials were marshaled at the Bradley Lake Powerhouse on 07/19/05. Inspection Site - The inspection site is located inside the Bradley Lake Tunnel Adit located at the North end of theBradleyLakePowerhouse.The Adit has an insulated plywood-sheathed weather protection Tunnel/Penstock Drain Iny,. -tion July 19,2005 Page 5 of 8 Bulkhead that was installed after the previous Part 12D inspection to provide a measure of protection for the facilities in the Adit during cold weather. The plywood wall sheathing and insulation were removed froma section of the wall to allow directaxialaccesstothetunneldrainsfromoutsideoftheAdit.This was to facilitate insertion and removal of the conductor conduit into and withdrawal from the 4-inch tunnel drains. The pictures below show the Adit wall with the plywood and insulation removed and the downstream ends of the tunnel drains. oer:- a 2 =po geecerwerregy eee eee2:a a wie elie wa boos :a P ye. .Phe |ip |- ==z ep .=|'i Te.. i i ae an a een oO:i 4.at if dedaneazenLaos ::so x To ge_i fo _ :amen)Ee|\:Co Or,ao !ra STeeeeee'HewesHlADIT WEATHER WALL WITH PLYWOOD REMOVED,CLOSURE HEAD VISIBIE.DRAINS TO LOWER LEFT OF HEAD. TUNNEL.DRAINS IN ADIT;SUMBERS INDICATE DRAIN SUMBER MARKED ON PIPE FLARGE. Details of Procedure for this Drain Inspection and Observations - Video Inspection began at 0730 hours and was completed at 1430 hours.Actual video inspection was from 0821 hours to 1359 hours with a short lunch break. The tunnel drains were first inspected without the use of the conductor conduit.This involved inserting the inspection camera into each drain in turn and pushing the camera as far into the drain as it was physically possible without damaging the camera.It was found possible to push the video camera into the drains a distance consistent with the 2001 inspection before progress became very difficult or was stopped completely. Next 60 lineal feet of conductor conduit was assembled and pushed into the drain and the inspection camera inserted and pushed through the conductor conduit into the drain and the camera again pushed as far as possible.This was successful in drains 1 and 2 but it was found that drains 3 and 4 had bends about 5 feet into the drain that prevented the insertion of conductor conduit past that point,thus the inspection of those two drains was limited to the non-conductor conduit technique. An additional length of conductor was added to the initial length and the camera again inserted in drain 1 and pushed as far as possible into the pipe.The camera and conductor were then removedfromdrain1andtheconductorwasmovedtodrain2andinserted.The camera was then inserted in drain 2 and run as far through the conductor and drain pipe as possible.The camera was then Tunnel/Penstock Drain Inspection July 19,2005 Page 6 of 8 removed and additional joints of conductor were connected to the existing conductor string toprovideconductortothestoppingpointofthepreviouscamerapushindrain2.The camera was again inserted and run as far through the conductor and drain 2 pipe as possible,then the camera and the conductor were removed from drain 2 and the procedure was repeated in drain 1.This process was repeated until a full 300 feet of conduit was inserted. With 300 feet of 1.5-inch PVC conductor installed it was found possible to reach the extent of the available camera umbilical,which was 298 to 311 feet,based on distances recorded from the SeeSnake.However,there were instances where the visibility was obscured either by calcinations breaking loose and occluding the camera lens or the camera being under water in dirty water (rust and calcinations particles).Attempts to clear up the water by flushing with freshwater from the powerhouse service water through the conductor were marginally successful at best. After the camera inspection was completed,an additional 200 lineal feet of conductor conduit was added to the 300 feet already assembled.The combined assembly was pushed into Drain 1 to determine if it is possible to provide the conductor to that depth to support a camera inspection to the 500-foot penetration indicated in the Part 12D inspection Report for 2001. It is concluded that this is a feasible technique for inserting the inspection camera the maximum distance,provided the camera can be equipped with a 500-foot or longer umbilical. Findings -- The 2001 camera inspection found calcination in the section of the drains downstream from the branch drain tees (drains to the powerhouse clean water sump)to have about 1/8-inch to 3/16-inch of calcite buildup un the pipe walls with some larger calcite nodules at various locations. Photographs of select locations in the drain pipes are included in Appendix 1.The drains upstream from the diversion tees could be seen in the 2001 video images as having calcite build up from that point upstream.Drain No.2 is noted as having the most flow in 2001.It is estimated from the 2001 video images that the 4-inch drain pipe called No.2 drain is occluded about 15%and significant amounts of calcite buildup can be seen beyond the drain diversion location. The current,2005,camera inspection found essentially the same conditions noted in the 2001 inspection.Drain No.2 is flowing the most water (no measurement was taken)and on all drains from the adit entry point to the branch drain tee there is,only a nominal buildup of calcination and rust on the pipe wall. Upstream from the branch drain tee,however,the calcinite buildup appears to be greater at this time than in 2001.It estimated that the calcite deposits upstream from the branch tees is reducing the open area of the drain pipe up to 35 percent of the 4-inch pipe cross-section,see Appendix 2. It was also noted that the physical scraping of the calcite during insertion and withdrawl of the conductor and camera was actually providing some reduction in calcite deposits through mechanical action.It would appear that the calcite deposit is generally not a "hard and fast”deposit in the pipe but can be removed with a moderately aggressive mechanical means. It was possible to achieve 300 feet plus camera penetration and 500 feet of conductor penetration ondrains1and2.Drains 3 and 4 have offset fittings close to the entry point and it was found not Tunnel/Penstock Drain Inspx.dion July 19,2005 Page 7 of 8 possible to push the conductor conduit through the offset section.Thus penetration could be achieved only by the unaided push camera to a depth of around 75 feet in those two drains. Conclusions- Conclusions reached as a result of this inspection are: 1 The push-type camera can be pushed into the drain pipe up to 500 feet using a conductor pipe and 500-foot plus umbilical. If the power/data umbilical is stiff enough or supported by a push rod of fiberglass as an aid the camera reach can be extended beyond 300 feet and perhaps to 500 feet.. If a SeeSnake type push camera is used,the self leveling type unit would transmit images that would be more easily interpreted as the image would consistently be oriented with the pipe invert "down”. The calcite buildup in the drain pipes upstream from the branch drain tees is becoming great enough that mechanical or hydraulic cleaning to maintain maximum flow area in the pipes should be done to ensure long-term functioning of the drains. As shown on Figure 8 it may be impracticable to push a camera farther than 500 feet up the drains because of mechanical obstructions presented by fittings in the pipes where the drains are realigned from positions around the liner to run along the back wall of the penstock manifold tunnel section. A smaller diameter camera and smaller diameter conductor may assist in performing a deep penetration inspection of Drains 3 and 4. Drain No.2 has the most water flowing in it,consistently. Branch drains from the tunnel drain pipes to the powerhouse clear water sump should be camera inspected to complete the current inspection record. Recommendations - We recommend that the tunnel drains be inspected in 2006 with a camera rigged with an umbilical capable of penetrating 500 feet into the four 4-inch penstock/tunnel drains;this includes the 2 drains having offset fittings near the outlet at the Adit. We recommend further study of the drain piping as-constructed record and market-available inspection cameras to determine the feasibility of installing smaller camera conductors and of penetrating deeper than 500 feet into the drain pipes with or without a conductor. We recommend water flushing of the branch drains from the power house to the tunnel drain pipes,in part to verify which branch drains are truly connected to each of the individual penstock/tunnel drains. Tunnel/Penstock Drain Inspection July 19,2005 Page 8 of 8 4.We recommend inspection of the branch drain pipes from the clear water sump and power house to the power tunnel in the near future. 5.We recommend evaluation of high pressure water cleaning of the drain pipes from the downstream end to as far past 500 feet from the outlet as practicable. Submitted June 12,2006 R&M CONSULTANTS,INC. Mf ohn K.Magee,P.E. ATTACHMENTS Aklschment f-l 1.Evaluate the relationship of the individual drains to the geologic structure mapped duringconstruction.Some limited field mapping may be necessary to confirm construction mapped geologic structure with field conditions. 2.Review the detailed water testing and grouting records to correlate water and grout takeswithgeologicstructureandmeasureddrainflows. 3.Measure the pressure in adjacent drains and the effect on temporarily plugging the drains on adjacent drains to identify the interconnectivity if any of adjacent drains or systems ofdrains. 4.Evaluate the effectiveness of the drains to intercept the foundation seepage and control the uplift on the spillway structure. 5.Make recommendations,if determined necessary,for additional monitoring instrumentation,remedial drainage,or remedial grouting. x The four 4-inch tunnel and penstock drains were partially video inspected in 1998 and 2001.References (23)and (24)report on the findings.The only drain with significant flow is Drain No. 2.In 1998 the flow was 20 gpm and in 2001 the flow was 15 gpm.The purpose of video(inspections was to evaluate the degree of calcite buildup in the drains.The calcite was estimated at about 1/8-inch and there was no detectable change between the 1998 and the 2001 inspections. \The drains appear to be functioning in accordance with their intended purpose. SECTION VI FIELD INSPECTION The Project facilities were inspected on September 4,5,and 6,2001.The weather was cloudy, windy,and with occasional light rain.The reservoir was at El.1174.2 on September 5,2001 when the upper facilities were inspected.Remy Williams represented the Alaska Energy Authority and participated full time during the inspection.William Mugula represented Homer Electric Association the contract operating agency during the upper facilities inspection.Robert Zacharski, Steven Pollack,and John Sherlock were available at the powerhouse to respond to questions and provide information on the Project. On September 5,2001,an aerial inspection was conducted of the upper facilities reservoir rim, Nuka Diversion,Middle Fork Diversion,and Upper Battle Creek Diversion.A helicopter was used for the aerial inspection.The upper facilities including the dam,spillway,reservoir outlet works gatehouse,fishwater bypass portal structure,and power tunnel gatehouse were inspected on the ground.The dam was observed from the crest and the toe and found to be in an excellent condition.Concrete on the upstream facing and crest was in good condition and did not exhibit signs of adverse weathering.The thick concrete crest and parapet wall did not exhibit any unusualcrackingorsignsofstructuraldistress.The portion of the upstream concrete facing that was visible did not indicate any cracking.The dam crest and parapet did not exhibit observable settlement or upstream/downstream alignment movement.The plinth and transition joints conveyor belting waterstop cover did not indicate any significant opening or offsets.The exposed waterstop appeared to be in a good condition.The downstream slope outer riprap zone appeared PAEABLR 26 11/12/01 tachment A-2 N.FUNCTIONING OF FOUNDATION DRAINS AND RELIEF WELLS No foundation drains are provided at the dam.The spillway foundation drains were functioningduringtheinspectionduetothehighreservoir.The spillway drains are functional. The penstock tunnel 4-inch drains embedded in the concrete lining behind the steel liner section of the power tunnel have been video inspected in the lower reaches and were found to be functional. Limited calcite buildup was reported.The inspection involved a video camera pushed into the drain line pipes from the upstream wall of the powerhouse and from the concrete tunnel plug in the North Adit.Reference 23 contains the full inspection report by Stone &Webster. Sustained flow measured in the 4-inch penstock drains was: Drain Line No.Flow (gpm) 1 Trickle 2 20 3 Trickle 4 Trickle Flows measured were reported comparable to flows observed during project startup in 1991 Penstock Drain Line 2 had about 1/8 inch calcite buildup.The other drain lines had less calcite buildup.The calcite buildup is in both layers and nodules.There was adequate flow area in the drain lines to maintain effective drainage. Recommendations were made in the Stone &Webster inspection report (23)to: 1.Inspect Drain Line 2 annually. 2.Locate video equipment capable of 500 feet of inspection in a 4-inch pipe. 3.Plan and schedule a plant outage and tunnel dewatering (probably within 10 years)to clean Drain Line 2.Actual scheduling will be dependent on continued calcite buildup and thickness of calcite layer. 4.Investigate availability of drain-cleaning equipment capable of cleaning 4-inch drains without dewatering the tunnel. The drain lines were inspected in October 2001 by the Alaska Energy Authority and no significant change in the buildup of the calcite was evident.The Independent Consultant concludes that based on about a 1/8-inch buildup of calcite in 10 years in Drain Line 2 that scheduling an annual inspection of Drain Line 2 may not be necessary.It is recommended that the next inspection should be deferred to 2006,the year of the next Part 12 inspection and hopefully by then equipment will be available to go into the drains 500 or more feet. PAEABLR 32 11/12/01 fe.pertKhmer AS | ¢It would be desirable in the winter at least once a month to fly over and visually inspectconditionsatthedamandspillway. D.ADEQUACY OF PROJECT OPERATION The Project is operated consistent with the operation and maintenance manuals and procedures.No deficiencies were noted. E.ADEQUACY OF OPERATION OF SPILLWAY GATES AND STANDBY POWER Not applicable as the spillway is ungated. SECTION XII RECOMMENDATIONS A.CORRECTIVE MEASURES REQUIRED FOR STRUCTURES No deficiencies were noted.No corrective measures are required. B.CORRECTIVE MEASURES REQUIRED FOR THE MAINTENANCE OR SURVEILLANCE PROCEDURES 1.Survey the movement monuments on the upstream face of the dam at El.1120 when the reservoir,through normal operation,permits safe access to the monuments. Survey the elevation of the tops of the spillway foundation drains. Implement an investigation and evaluation of the significance of the spillway foundation drain flows and pressure readings described in Section V. Floating wood debris from above the power intake and reservoir outlet intake should be removed more frequently on an as needed basis to prevent it from sinking and plugging the intake trashracks. Repair damaged gabions on both sides of the Nuka Diversion Outlet Structure. .Repair eroded Upper Battle Creek upstream embankment dike slope and chanelize the waterfall stream delta. PAEABLR 11/12/01 The next video camera internal inspection of the power tunnel and penstock drain lines should be performed in 2006 prior to the next Independent Consultant inspection and = as noted in Section VI hopefully inspection equipment will be available to inspect up to y 43 LA'achment B-t APPENDIX H REFERENCES 14.Technical Paper No.52,Two-To Ten-Day Precipitation For Return Periods of 2 to 100 Years In Alaska,U.S.Department of Commerce,Weather Bureau,1965. 15.Bradley Lake Project,Tunnel Inspection Report,Spring 1992,Stone &Webster EngineeringCorporation,September 1992 16.Hydraulic Model Study of Bradley Lake Hydroelectric Project,Colorado State University, January 1987 17.General Civil Construction Contract,Bradley Lake Hydroelectric Project,Volumes 2,3,and 6,Stone &Webster Engineering Corporation,June 8,1988 18.Middle Fork and Nuka Diversions Construction Contract,Bradley Lake Hydroelectric Project, Volume 2,Stone &Webster Engineering Corporation,December 14,1989 19.Bradley Lake Hydroelectric Project,Project Construction Historical Report,Volumes I &II, Alaska Energy Authority 20.Completion Design Report,Bradley Lake Hydroelectric Project,Stone &Webster Engineering Corporation,January,1992 Additional references used in preparation of current report: 21.Initial Independent Consultant Inspection Report,Bradley Lake Hydroelectric Project,Donald E.Bowes,P.E.,October 1996. 22.Supplemental Independent Consultant Inspection Report,Bradley Lake Hydroelectric Project, Donald E.Bowes,P.E.,March 1999. 23.Tunnel Drain Assessment,Bradley Lake Hydroelectric Project,Stone &Webster,September25,1998,Letter Report. oe '"24,Bradley Lake Hydroelectric Project,Tunnel Drain Video Inspection,Spillway Drain Flow and Pressure Readings,R.G.Williams,Inc.,October 5,2001,Letter Report.wy PAEABRAPPE-H 11/1201 812 p.2 Attachment B2 R.G.WILLIAMS,Inc.P.O.Box 876688 Wasilla,AK 99687 Phone (907)376-9035 -2 Fax (907)376-9036 a October 5,2001 Donald E.Bowes,P.E. Consulting Engineer 16225 S.E.29th Street Bellevue,WA 98008 Subject:Bradley Lake Hydroelectric Project Tunnel Drain Video Inspection Spillway Drain Flow and Pressure Readings Dear Don: Enclosed is a VHS tape of the Bradley Lake tunnel drain line video inspection, which was performed on 10-2-01.John Christensen of American Marine Corporation and myself performed the inspection.From the powerhouse wail, we were able to insert the camera 73'into drain 1,73'into drain 2,75'into drain 3 and 67'into drain 4.From the adit,we were able to insert the camera 84'into draint,77'into drain 2,127°into drain 3 and 152'into drain 4.|could not detect a significant change in the build-up in the drains from the previous video inspection.As before,drain 2 was the only drain with a significant amount of flow.|measured the flow in drain 2 at 15gpm.|am also enclosing a photo of the liner drains in the adit. !am also enclosing for your information,the spillway drains flow and pressure in Attach gutreadingsform9-17-01,9-27-01 and 10-2-01. Please contact me if can be of further assistance. a Swiame,P.E. Owners Representative cc Stan Sieczkowski,AEA w/o enclosures Attachment b-3 Tad sa adsae inyCfbeeheLh.”enge<.nHancerheatiednnte.erre31AlesWertaly18,Ap9SBEAaeme!qotau<9«he<aersus|deteatmeeeeTTt,',yut1p,hte.>fv)bs7sohhastoeRieti'fyi.EHSi"ene.<jadsThe above photo shows the Bradley Lake tunnel liner drains as they exit the concrete bulkhead in the north adit.The numbers are as indicated on the flanges when the drains were video inspected on 10-2-01.|am certain drain no.2 is correct because drain no.2 is the only drain making a significant amount of water and you can hear water flowing in drain indicated as no.2.|am also certain drain no.1 is correct as indicated because when the drain was videoed we could see the "T"where the drain branches off along the penstock to unit #1.(We could also see a "T"in drain no.2 at about the same location.)|was unable to confirm that drains 3 &4 are correct as indicated.(The numbers could be transposed,however,at this time,|have no reason to believe they are.)The numbers on drains 3 and 4 will have to be verified by flow testing. Remy G.Williams 10-4-01 Attachment B-A- PENSTOCK MANIFOLD TUNNEL CLOSURE HEAD 3 PENNSTOCK MANIFIOLD TUNNEL DRAINS SKETCH SHOWING ARRANGEMENT OF DRAINS AS REPORTED BY Remy Williams,P.E.10/4/01 REF &r-1610 FIGURE 1 -BRADLEY LAKE POWER TUNNEL LINER AND PENSTOCK LINER -SCHEMATIC PLAN Not To Scale Reference Drawings H05-F-31-5001-R49 and H05-F-31-50016-R49 ata - :dhe |POWER TUNNEL LINER }>Se |ld * ae aay %TUNNEL TO PENSTOCKrr)-,ae eLow -CURVED TRANSITION_uyONCLINEDtpSTEELLINER4eooctionsa40sae--An 2 =Ri ;AC Oo"72th aFP4161SERIES9SECTIONS@40':HOO |it SECTIONS @ ¢560-9")ti"te ey sy uh t:¥ B 9 off os 148 23 24 2atjp2e 39 49 6l 6s é |- ;66.50 (7 :T 2 TT 4 pity #a 2 wrt J+-pt J a |ar)-7 ey St &i £2 =yn -wheel .eee 1}TI r er T I i t it Jf.I i _'°.Tt 7,i L eS ' Ce 70.48 vp a pe t616 6-9) dl uv Prec WE FELD WELOS PER ro ' SDE TA GIFS 16 :we =:Sip Pe oan ep rican T Seif BeTalL J O€TaiL «(Joa SiA BSWTe aEaawea|anee.NERSee ae 276 _ere 7 i P2 i Mage ya:|1 [PRE aORBRACKE TT ye Ip a =CROWN CcHtALtpeeSEESasoaTeaayTRAINeaeD TRIPE SUPPORT BR ACARTI TYP?Le \tule DESC FB ane --|on eeas \|roAW Neer wife J --- aS NS.WS or.eM RO +m...bneel BRAT HOLES 7 &Big t-O'LAL ROM eo A_|(BOWS STAGBER ED i -_ _4073)-a a &SCHNT 3 UPSTREAM LINER NO.1 TYPICAL.STEEL LINER SECT ON (42 RED UNER 2-63) FIGURE 2 -UPSTREAM END OF TUNNEL LINER FIGURE 3 -TYPICAL SECTION OF TUNNEL 2Vanae WEL .a 7 ae av ;SR PE Su eT ©baa:OF os ''a BRACKET,of”1 : i SCREWED Lo PLS Lf AFP.Le ONE,\op eek aeBOCKtePorees"a ONS Ly fe Ti ge BeeASTMAZB4'NFa 2 r fp ----anenige .ro a8 a57 *- *ae.a a -_ |a [3 fog B --"par AY |nS Fe ; i ----.Z on *a =Steet Hoan]\raser now sts lev ="AC¢HEAD PLUG +TASTM A234 'APB f Aho 1 eyeARETMASSAWPCreekweTRATTTh2_4 oe, -”HTS Re x Sor <°Sore42 AF EEP POLESDETAILarudegxa.--4 DETAIL B ee 5 sane AUG OS SPo-4 >(Comat y SCALE A astm SCALE 8 DETAIWOTERSTE FIGURE 4 -DRAIN PIPE DETAIL AT UPSTREAM END OF TUNNEL FIGURE 5 -TYPICAL DRAIN FIGURE 6 -TYPICALTAPINTOROCKINTERMEDIATEDRAINPIPE cEeTaLs -* DETAIL O(G3)FIGURE 7 -TYPICAL SLIP_ COUPLING IN DRAIN LINES Alaska Energy Authority Bradley Lake Hydroelectric Project FERC No 8221-AK POWER TUNNEL/PENSTOCK DRAIN INSPECTION JULY 19,2005 ATTACHMENT C,SHEET 1 of 3 POWER TUNNEL/PENSTOCK LINER PLANS AND DETAILS Raterence Drawings HOS5-F-31-0015-R49,HO5-F-31-3020-R49,H0S-F-31-5001-R49,HO5-F-31 -5002-R49,HOS-F-31 -5006-R49,HOS-F-31-VHO5-D-31-V5118-R49,and HOS-D-31-V5131-R49 |)ee SN KM |January 26,2006R&M CONSULTANTSG,INC. GSSrtrWSCee »GTUNHE-22 46>aa }, we tae i a ee oe PEL i ; %GROLT HOLES "ts TUNNEL DRAIN ue LONERS Saf-a ONLY)7 DRAIN PIPES PEAS oh PIPE.TYPICAL Oy ypALONGTUNNELoeNe:Sy #WALL a gb "he Berg.' __ $-"---€STE LNER 9-9 '*e 'FIGURE 10 -TYPICAL SECTION OF TUNNEL UPSTREAM FROM CURVED TRANSITION FIGURE 9 -TYPICAL SECTION OF TUNNEL AT PENSTOCK SCALE St les oe FIGURE 8 -PLAN -PENSTOCK/MANIFOLD SHOWING ROUTING OF TUNNEL DRAIN PIPES ©RYN CONTACT ¢:BRCUT ROLE ©TUNNEL SyM™ABi ITP STAGGERED»©TUNBEL P-§RAN TRgleCS,STAGGERED: - neg Ha STUD eo iweyaniDETAILF-\-| (B-9)a ne See, "EM EEES Nght Alaska Energy Authority ic | Bradley Lake Hydroelectric Project oe EE FERC No 8221-AK POWER TUNNEL/PENSTOCK DRAIN INSPECTION JULY 19,2005 h . 7 ; sto STD ORAIN-T ,So hd4SSAISRB° GPL ae Sn me eh,SPRIV -rt ne omirten -WATERS TCP TOLL AR M,FOR CLAHIT«272 e383,a ATTACHMENT C,SHEET 2 of 3 FIGURE 11-TUNNEL CROSS-SECTION FIGURE 12-TUNNEL CROSS-SECTION FIGURE 13 -TUNNEL TYPICAL.POWER TUNNEL/PENSTOCK LINER AT UPSTREAM END OF LINER AT UPSTREAM WATERSTOP CROSS-SECTION WITH LINER PLANS AND DETAILS WE 8.NT ik |vanuary 26,2006|Reference Drawings HO05-F-31-0015-R49,HO5-F-31 -3020-R49,HO5-F-31-5001-R49,HO5-F-31-5002-R49,HOS-F-31-5006-R49,HOS-F-31-VHO5-D-31-V5118-R49,and HOS-D-31-V5131-R49 REM CONSULTANTS,INC. -_----_--x -SROUT AND VENT PIRES ooo!020"loco ,a SEE Gwa EN4-CC-069 ;--------e =.a nd ,=SaaS =FIG 17é.¥s, ie ee eee See ee i Se an an POUR TRS oe __14 | cng grey =# 4 precpivd|zog|suo |s WE Ww 2 $ My :6 _WOE Aa Be 88.05 " PUUK Mibas a 7 oS a f is j es ¢8A:Ga Eu 22 $0 8 J if --T ft Dee T 7 .BAAN EAN &i, a on a ee ee a :Hen m UF Ng sa I i OTe od Ant --tt 1940 TYP To , 1 >T --,*owe|°2 jt a .A POUR MTA -oh)STs 3491 48 _-_ -7.50 A Lo 7 cece dil oe Cu tii?se gL 720 alk -Vee ey fe fae :rho '"|I Tor sumports.see ens coaso-+|;|"-'ype a|)-=----PLACE M7BZ PRIOR TU 2 ol |Ss ;|i) o .gi 8 SETTING LINER &sUReRAT "POUR MTB?=|@ x zi 2 =!Fy 2 x 3 oe &.bd 2 2 i =2 s ]5 4 _pts Fk 89 +:2 *”a x d-|'|=!ea =a .he ;RI F}:|a \POUR MIBE ""al real : <a BSih|i.EL 1003 ee !__1.;_ m i "e 5 3 *, 3]'|= FIGURE 14 -PENSTOCK LINER SHOWING DRAIN PIPE AND BRANCH DRAIN ROUTING -- >FIG17 @ TUNNEL48'-0"PENSTOCK THRUST BLOCK i POWERHOUSE GENERAL CIVILCONTRACTCONTRACT2.0"EXTENSION TOGRADEIF ¥=COVERED WITH BA4CKFILL. i WAVE EXTENSJieOFSTEN wreT4 eT CONC THRUST BLOCK OY <3"eye ag RAIN REIT YR r-9 i G EL 124.07 ° oe :e |4 x LONTRACTOR TO ADJUST ROUTINGwalesngTOALLOWPLACEMENTOFVALVESaoFSSstrvey: "hea "ak . a de|so -TRIM FITTNGS TO re"7 Bes =.ACTOMMOMATE ANGLE (TYA)2.Tats VALVES TO CLEAR FUEL STORAGE TANKUNIT1ONLYCLEARANCE TEMPORARY ORAIN LINE BYCONTRACTOR or"oe 300#RFE FLGS GASKETS ARE FLAT RING TYPE 304StoeeeRBFILLERV8"THK.RING PER ANSI? [300 4*FULL PORT BALL VALVES WITHJOCLBRFFLANGE(TYP)LINE TS 5S'OTF ROM -RF FLG,CS BOOY,BALL &STEM AND TEFLON"MyM {<OF PENSTOCK 12 ate SEAT&SEALS.(TYP.4)CRANE VALVE OR EQUAL(2-8) f©-8,G-8) FIGURE 15 -DESIGNED ROUTING OF DRAINS AT DOWNSTREAMEND -THIS IS NOT DETAIL AS- CONSTRUCTED -FOR INFORMATION ONLY FIGURE 16 -TYPICAL BRANCH DRAIN PIPE ROUTING TO POWERHOUSE CLEANWATER SUMP S"OR AIM PIPES. REF BY-26°C we |ge &£GROUT HOLES -*- fLiMERS 33-63 Ofer?H DETAIL F -(sea 39 {FELD ROUTE) "ESTEEL NER FIGURE 17 -TYPICAL TUNNEL CROSS- [Reference Drawings H05-F-31-0015-R49,HOS-F-31 -3020-R49,HOS-F-31-5001-R49,HO5-F-31-5002-A49,HO5-F-31-5006-R49,HO5-F-31-VHO5-0-31-V5118-R49,and HO5-D-31-V5131-R49 SECTION AT PENSTOCK Alaska Energy Authority Bradley Lake Hydroelectric Project FERC No 8221-AK POWER TUNNEL/PENSTOCK DRAIN INSPECTION JULY 19,2005 ATTACHMENT C,SHEET 3 of 3 PENSTOCK LINER DETAILS mee 2 &..1/1REMCONGULTANTE,ING. JKM January 26,2006 Attachment D PHOTOGRAPHS OF THE BRADLEY LAKE POWER TUNNEL LINER DRAIN PIPES From Bradley Lake Photo Archives of 1990 08/27/90 -Unloading tunnel liner,note 4-10/18/90 -Installing Penstock Manifoldinchdrainpipesattachedtoliner.closure head in adit;drain pipe outlets at lower left. an a 08/27/90 -Unloading tunnel liner,note 4- inch drain pipes attached to liner.11/04/90 -Liner section entering tunnel adit. -7 ae =:>_ ; oa rh Oey, Tem :s by ' ®FY i 7eo/:_\7 iseab4.See Oe,==A *pees:an za ms = 10/16/90 -Placing mud slab for tunnel liner 11/04/90 -Liner section in tunnel,note drain installation track.pipes attached to liner. Bradley Lake Penstock/Tunnel Liner Construction Photographs,1990 Page 1 of 2 Attachment D OeoneaweeatenOeqe6Gstnem14)-,.11/20/90 -Typical drain pipe sliding coupling at connection point. 12/10/90 -Connected drain at right of picture. 3 ee/4 =i a rf .;WeWinea!ieainiey,enPRATaeeeseae"fl|lly;oaod1..h"1eloa:'eott.412/11/90 -Drain pipe at coupling connection 12/12/90 -Top of liner in tunnel before concrete placement,note drain pipes at left and right of liner. Bradley Lake Penstock/Tunnel Liner Construction Photographs,1990 Page 2 of 2 APPENDICES APPENDIX 1 -IMAGES FROM VIDEO TAPES OF CAMERA INSPECTIONS OF 4-INCH PENSTOCK/TUNNEL LINER DRAINS 2005 CAMERA INSPECTION IMAGES Photos are video-stills from video tape of 2005 inspection. [VIEW [COMMENTS 2005-1 -Typical Drain at 7 feet from outlet COMMENTS- ae Typical thin coating of calcination on pipe af |wall,heaviest in invert.Thickness estimated at around 1/4 -inch to 3/8-inch.PnaeseerSUSEZI0 COMMENTS- rm ua Ta ead Typical thin coating of calcinations on pipe Poe a gee wall,heaviest in invert.Thickness estimated at around 1/4 -inch to 3/8-inch.M2& APPENDIX 1 -Tunnel/Penstock Drain Inspection Report 07/19/05 Page 2 of 11 2005-3 -Typical Drain at 49 feet from outlet "eerefe,rahidAhdewMhabseitemge-eldttianeCOMMENTS- Typical thin coating of calcinations on pipe wall,heaviest in invert.Thickness estimated at around 1/4 -inch to 3/8-inch. 2005-4 -Typical Drain at 78 feet from outlet Agreeafenonefifety2meA).pag438)ad&s%onaCOMMENTS- Typical thin coating of calcinations on pipe wall,heaviest in invert.Thickness estimated at around 1/4 -inech to 3/8-inch. APPENDIX 1 -Tunnel/Penstock Drain Inspection Report 07/19/05 Page 3 of 11 2005-5 -Typical Drain at 280 feet from outlet COMMENTS- Caleination ts built-up in the invert of the drain pipe to approximately the springline. |This view is underwater ina "sag”or backwatered section of the drain line. |Water surface is at top of photo. Ue -wens as LbByeu =we we -te -i: COMMENTS- |Calcination is built-up in the invert of the 'drain pipe to approximately the springline. y Caleination APPENDIX 1 -Tunnel/Penstock Drain Inspection Report 07/19/05 Page 4 of 11 2005-7 -Typical Drain at 303 feet from outlet etaes - ae a oot a Pn COMMENTS- Calcination is built-up in the invert of the drain pipe to approximately the springline. CaleinationYY 2005-8 -Typical Drain at 311 feet from outet COMMENTS- Thick Caleination is built-up in the invert of the drain pipe to approximately the springtine. APPENDIX 1 -Tunnel/Penstock Drain Inspection Report 07/19/05 Page 5 of 11 2005 CAMERA INSPECTION IMAGES Photos are video-stills from video tape of 2001 inspection. |VIEW |COMMENTS | 2001-1 -Typical Drain at Branch Drain Fitting 78 feet from outlet COMMENTS- Typical thin coating of calcination on pipe wall,heaviest in invert.Thickness estimated at around 3/8-inch to 1/2-inch. Note calcinations buildup around inlet to branch drain. 2001-2 -Typical Drain at Branch Drain 77 feet from outlet (different drain than |above). Calcination buildup around inlet to branch -- ,_-|drain.iave-awl 13:33:SLs)LE aCratePUPSVIDEOTEPEsTiG--: APPENDIX 1 -Tunnel/Penstock Drain Inspection Report 07/19/05 Page 6 of 11 2001-3 -Typical Drain at 90 feet from outlet COMMENTS- Typical thin coating of caleinadions on pipe wall,heaviest in invert.Thickness estimated at around 1/8-ineh to 3/16-inch. 2001-4 -Typical Drain at 136 feet from outlet COMMENTS- Typical thin coating of calcinations on pipe wall,heaviest in invert.Thickness estimated at 1/8-inch to 3/16-inch.edentinewii APPENDIX 1 -Tunnel/Penstock Drain Inspection Report 07/19/05 Page 7 of 11 1998 CAMERA INSPECTION IMAGES Photos are video-stills from video tape of 1998 inspection. [VIEW [COMMENTS | 1998-1 -Typical Drain at Branch Drain fitting about 78 feet in. COMMENTS- Typical buildup of calcination around drain branch inlet.Thickness estimated at around 3/8-inch to 1/2-inch. [998-2 -Typical Drain at 38 feet from outlet COMMENTS- Typical thin coating ofcalcinations on pipe Vi wall,heaviest in invert.Thickness estumated ataround L/8-inch to 3/16-inch. APPENDIX 1 -Tunnel/Penstock Drain Inspection Report 07/19/05 Page 8 of I1 1998-3 -Typical Drain at around 50 feet from outlet gr ERonwaete rs ty,wevertuitsaesresnoTTketLARSEe,COMMENTS- Typical thin coating of calcinations on pipe wall,heaviest in invert.Thickness estimated at around 1/8-inch to 3/16-inch. 1998-4 -Typical Drain at 78 feet from outlet COMMENTS- Typical thin coating of calcinations on pipe wall,heaviest in invert.Thickness estimated at around 1/8-inch to 3/16-inch. APPENDIX 1 -Tunnel/Penstock Drain Inspection Report 07/19/05 Page 9 of 11 2001 CAMERA INSPECTION OF THE BRADLEY LAKE POWER TUNNEL BRANCH DRAIN PIPES Photos are video-stills from video tape of 2001 inspection. [VIEW [COMMENTS _| BD20G1-1 -Typical Branch Drain at l-foot from outlet COMMENTS- Typical thin coating of calcination on pipe wall near outlet.Thickness estimated at around 1/8 -inch. BD2001-2 -Typical Branch Drain at 16 feet from outlet COMMENTS- <--*Typical thin coating of calcinations on pipeTng8si"I wall thickness estimated at around [8 -inch, ae APPENDIX 1 -Tunnel/Penstock Drain Inspection Report 07/19/05 Page 10 of 11 BD2001-3 -Typical Branch Drain at 17 feet from outlet COMMENTS- Typical thin coating of calcinations on pipe wall thickness estimated at around 1/8 -inch with nodules up to 1/4-inch thick. This is different drain than 2 above. BD2001-4 -Typical Branch Drain at 30 feet from outlet COMMENTS- .Typical thin coating of calcination on pipe a _"||wall.thickness estimated at around 1/8-inch. APPENDIX 1 -Tunnel/Penstock Drain Inspection Report 07/19/05 Page 11 of 11 BD2001-5 -Typical Branch Drain at 37 feet trom outlet COMMENTS- Caleination is built-up in the invert ofthe drain.thickness estimated to be £/8-inch to 1/4-inch. BD2001-6 -Typical Drain at 7!feet from outlet ==COMMENTS- Calemation is built-up in the invert of the drain,thickness estimated to be 1/8-inch to i/4-inch.This is just downstream from the branch fitting inlet from the tunnel drain. 5 s BD2001-7 -Typical Branch Drain at 73 feet from outlet COMMENTS- Calcination is built-up in the invert of the drain,thickness estimated to be 1/8-inch to 1/4-inch.This at the branch fitting inlet from the tunnel drain. Appendix 2 Bradley Lake Penstock/Tunnel Drains Inspection 2005 CALCINATION BUILDUP ESTIMATE VIDEO INSPECTION WAS MADE FROM INLET TO 310 FT INTO DRAINS AND FOUND CALCINATION BUILD-UP. THIS CONDITION EXISTS FROM ABOUT 125 FEET TO 310 FEET FROM FLANGED OUTLET AT END OF PENSTOCK TUNNEL LINER AND SUSPECTED TO EXIST BEYOND 310 FEET. APPROXIMATELY 35%OF THE CROSS-SECTION IS OCCLUDED,LE..OPEN AREA IS APPROXIMATELY 65%. J.K.Magee,P.E. 10/12/05 3S/M! R&M CONSULTANTS,INC.