B08__A8_Concrete_Technical_Memorandum_2.pdf

Technical Memorandum

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Concrete Evaluation (Task 14)

Date: October 2023 Jacobs Engineering Group Inc.

999 W. Main St Suite 1200 Boise, ID 83702 United States

T +1.208.345.5310 www.jacobs.com

Project Name: Wapato Irrigation Project Drop 1 Pumping Plant Water Screen, Pumps, and Structure Condition Assessment, Conceptual Design & Feasibility Study, Design, and Construction Management – Phases 1 and 3

Project No.: D3673800

Attention: Tim Sauer, P.E.

Client: Bureau of Indian Affairs

Prepared by: Howie Henrikson, P.E.

Reviewed by: Kent Soelberg, P.E.

Document No.: 231005074011_bad7e8aa

Contract No.: 140A1218D0020/140A1622F0179

1. Task Order Overview Under Architect-Engineer Contract Number (No.) 140A1218D0020, Jacobs was retained by the Bureau of Indian Affairs (BIA) to complete a condition assessment and design work at Wapato Drop 1 Pumping Plant (facility) in south central Washington, on the Yakama Indian Reservation. The facility is an integral part of the Wapato Irrigation Project (WIP), and BIA performs operations and maintenance of the WIP.

Because of the age of the Drop 1 Pumping Plant and deferred maintenance over the years, the facility has developed many known and potential deficiencies. As a result, BIA issued Task Order No. 140A1622F0179 to Jacobs to complete a series of tasks described in BIA’s Statement of Work (SOW). Jacobs is currently engaged in the execution of SOW Phase 1 Water Screen Design and Phase 3 Drop 1 Condition Assessment.

2. Wapato Drop 1 Pumping Plant Description The WIP provides irrigation water to approximately 140,000 acres of farmland within the WIP boundaries.

The existing WIP Drop 1 Pumping Plant is located approximately 8.2 miles south of Yakima, Washington, in Section 36, T12N, R13E, WM. The Drop 1 Pumping Plant is on the WIP Main Canal, approximately

4.4 miles downstream from the Yakima River diversion headworks.

The Drop 1 Pumping Plant is an integral component of the WIP Main Canal System that lifts up to 165 cubic feet per second (cfs) of water to serve approximately 7,000 acres of upper land along the northwest perimeter of the Project. The Drop 1 Pumping Plant structure is also a distribution junction for the Main Canal, with water being divided into the East and West Highline Canals (up to 165 cfs), the Main Extension Canal (up to 225 cfs), and drops into the continued Main Canal (up to 1,500 cfs).

The Drop 1 Pumping Plant was completed in 1929 and consists of the following:

A pumping plant structure and discharge pipeline serving the Unit 1 (East and West Highline) Canals

An attached gated drop structure and spillway (to pass Main Canal flows downstream when there is excess to hydraulic turbine pump needs or when the pumps are off)

An attached gated headworks structure serving the Main Extension Canal

Suspended electrical pumps that supplement flows to the discharge pipeline serving the Unit 1 canals

20 Oct 2023

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3. Scope of Document This document provides the findings and recommendations resulting from the condition assessment of the concrete for the Drop 1 Pumping Plant, including the spillway and drop structure, discharge pipeline encasement, Main Extension Canal headworks, and tailrace. Refer to Forebay Concrete Evaluation (Task 3) prepared by Jacobs dated May 18, 2023, for findings and recommendations for that portion of the facility.

4. Approach Generally, an initial review of existing facility drawings is very helpful to identify potential defect areas for inspection focus based on original detailing. Drawings of this type can also help inform why certain defects are observed. However, in this case, there are a limited number of drawings available, and some that are available may be preliminary drawings that don’t reflect the as-built condition.

The condition assessment included an activity to identify visual concrete defects and also collect some core samples of existing concrete for compression testing and petrographic analysis. The visual defects were marked and mapped between November 16 and November 18, 2022, with survey technology.

Defects were field marked with spray paint and labeled with a crack designation. Cracks on vertical elements higher than could be reached with a paint can from a standing position were not marked.

Reachable cracks were marked with spray paint along the length of the crack. Spalls were identified by a spray-painted perimeter.

Approximate locations for taking nominal 4-inch-diameter cores were also painted and labeled. For purpose of taking core samples, the facility was divided into five basic elements including forebay floor, forebay walls, discharge pipe encasement, tailrace floor, and tailrace walls. Six cores at each of the five elements were planned. Five of the cores intended for compression testing and the sixth intended for petrographic analysis. The drawings in Attachment 1 show the approximate core locations on the facility.

Some slight variability expected due to avoiding existing reinforcing locations. The number of cores for testing was to better establish a concrete strength for each element. Core extraction occurred on January 17 and 18, 2023.

5. Crack and Defect Mapping Typical defects are as described as follows:

Typical temperature and shrinkage cracking was observed in various elements—especially elements with larger length to width aspect ratios.

Concrete surfaces below normal operating water levels exhibited loss of fines between aggregates.

Loss of fines varied between essentially no loss for some elements and severe loss for others.

Some spalling and exposure of reinforcing was noted.

The upstream divider walls between siphon and gate bays exhibited some cracking and spalling where reinforcing appears to be corroding and expanding.

The underside of the elevated concrete deck over the siphon bays and spill gate bays is spalled with exposed reinforcing except in the right-most spill gate bays where the element was replaced with new concrete.

The right downstream training wall corner exhibited spalling and exposure of corroded reinforcing steel.

The concrete encasement around the discharge pipe exhibited map cracking at the surface, and sounded very punky with hammer taps, and exhibited stalactite type formations on the underside.

Petrographic testing of a partial cylinder sample confirmed that alkali silica reactive (ASR) aggregate is not present. However, air content tested at 7% to 8%, which seems unusual for concrete of this vintage. Five of six of the cores basically came apart between aggregates during attempted drilling

231005074011_bad7e8aa 3 and extraction such that a sample could not be taken to test for strength. The concrete in the pipe encasement is deteriorated and in very poor condition.

The tailrace slab was particularly eroded, especially downstream of the gate and siphon spill bays, including some exposure and corrosion of reinforcing steel. The petrographic concrete testing showed particularly low air content, which suggests the concrete is vulnerable to freeze/thaw damage where elements are wet (like the floor) in cold weather. The tailrace slab downstream of the gate and siphon bays is in poor condition.

Crack widths are difficult to determine in concrete surfaces where the top part of the surface is eroded, scoured, or abraded as crack edges tend to round off and present much wider than they are. This is generally the case where cracks are below canal operating levels. Due to this condition, crack width.

Estimates were not attempted.

Attachment 2 provides crack and defect mapping.

6. Concrete Core Strength Testing Concrete strength appeared to be fairly high for the forebay slab, forebay walls, tailrace walls, and tailrace slab. An f’c value adjusted based on number of tests (generally five) for each typical element and the standard deviations is larger than 4000 pounds per square inch. As previously noted, intact core samples could not be obtained from the discharge pipe encasement to verify strength. However, discharge pipe encasement concrete is significantly deteriorated. Attachment 3 provides results from concrete core compression testing and a summary reduction of the data.

7. Concrete Core Petrographic Testing Petrographic testing was completed on one core for each of the five typical elements. However, the discharge piping encasement was a partial core depth as the cores did not stay intact after drilling and extraction. Key results indicate the following:

Coarse aggregate generally mostly basalt with some sandstone.

Fine aggregate generally crushed, clean, well distributed similar rock fragments, quartz, and feldspar grains.

Original concrete showed an air content consistent with concrete placed without added air entraining (3% or less).

Forebay floor known to be more recently replaced had air content of 5% to 6%.

The discharge pipe encasement analysis showed 7% to 8% air entrainment, which seems like a questionable result.

The tested cored in the forebay wall exhibited a low level of ASR due to some reactive quartz grains in several sandstone particles. The opinion of the testing firm was that reaction had run its course and was no longer active.

Portland cement was generally well hydrated.

Carbonation depths were as much as 2 inches on the discharge pipe encasement sample, but more like 0.25 inch in other samples.

Apparent water/cement ratios varied between 0.42 and 0.51.

Attachment 4 provides results from petrographic analysis.

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8. Condition Assessment Terminology This section outlines concrete condition assessment general distress categories and concrete condition assessment terminology definitions.

8.1 Concrete Condition Assessment General Distress Categories Chalking/Dusting – formation of a loose powder resulting from the disintegration of the surface of concrete

Cracking – A separation of concrete into two or more parts produced by breaking or fracturing

Delamination – A separation along a plane parallel to a surface

Disintegration – Reduction into small fragments subsequently into particles

Scaling – Local flaking or peeling away of the near surface portion of hardened concrete

Spalling – A fragment detached from a concrete member by a blow, by the action of weather, by pressure, by fire, or by expansion within the larger mass

8.2 Concrete Condition Assessment Terminology Definitions

The general definition of condition assessment terminology is as follows:

EXCELLENT CONDITION – Structure, two years or less in age, with no noticeable deficiencies.

VERY GOOD CONDITION – Structure older than two years of age with no noticeable deficiencies. No visible cracking.

GOOD CONDITION – Minor problems. Minor shrinkage transverse or random cracks with light scaling (less than 1/4 inch depth with exposed aggregate). No spalling. Minimal hairline cracks with no disintegration of concrete. No staining present. Minor shrinkage cracks, H/L to 1/32 inch light scaling, or insignificant spalling which does not expose reinforcing steel. Insignificant damage caused by drift or collision.

SATISFACTORY CONDITION – Structural elements show minor deterioration. Minor deterioration of surfaces. Minor hairline to 1/16 inch cracks with no disintegration of concrete. Minor leaching and/or staining present at cracks in elevated elements and walls. Sealable cracks. Medium scaling (1/4 inch to 1/2 inch in depth), 2% or less of the concrete scaled.

FAIR CONDITION – All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. Moderate 1/16 inch to 1/8 inch cracks in concrete. Considerable leaching and/or staining through elevated elements and walls at cracks. Heavy scaling (1/2 inch to 1 inch in depth) Partial but no full depth failures of elevated elements. Scaling and Spalling do not expose reinforcing steel 2% to 5% of concrete scaled.

POOR CONDITION – Advanced section loss, deterioration, spalling or scour. Larger than 1/8 inch cracks in concrete. Heavy leaching and/or staining present at cracks in elevated elements and walls. 5 to 50% of the concrete scaled. Full depth failures are imminent. Spalling is beginning to expose reinforcing steel. Many concrete elements show substantial loss with exposed reinforcing steel.

Minimal loss of bearing area of elevated elements.

SERIOUS CONDITION – Loss of section, deterioration, spalling or scour have seriously affected primary structural components. Local failures are possible. Greater than 50% of concrete element scaled. Small full depth failures. Serious disintegration of concrete. Many open cracks may be present. Reinforcing steel is exposed and rusting. Structural cracks in concrete elements.

CRITICAL CONDITION – Advanced deterioration of primary structural elements. Shear cracks in concrete may be present or scour may have removed substructure support. Full depth failures in

231005074011_bad7e8aa 5 elevated concrete elements and wall. Concrete disintegrated on critical members. Reinforcing steel severely corroded. Considerable loss of bearing areas under elevated elements.

9. Observation Summaries This section provides observations of the forebay walls and floor, tailrace walls and floors, and elevated concrete elements.

9.1 Forebay Walls

Forebay walls include the following elements:

Intake screen bays Siphon and spill gate bays Left training wall Interior training wall Right training wall Pumping plant turbine inlet walls Powerhouse north wall Main extension canal inlet

9.1.1 Intake Screen Walls

The intake screen walls are cast-in-place concrete elements. Intake screen bay walls isolate each of the three intake turbine bays and each turbine intake bay is further divided by an interior divider wall. The late 1920s original construction of the intake screen walls was extended upstream at some later date, which included steel angle armored edges on the upstream corners of the intake screen walls and also some steel ladder rungs associated with trash rack cleaning on every other intake screen wall ( Figures 9-1 and 9-2). The extensions were added upstream of the inclined trash rack panels. The intake screen walls are in satisfactory condition with minor surface scaling of the concrete. Long term, the exposed embedded carbon steel elements may cause some spalling as the carbon steel expands during anticipated future rusting.

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Figure 9-1. Upstream View of Typical Turbine Intake Bay Walls

Figure 9-2. Typical Side View of Turbine Intake Bay Wall

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9.1.2 Siphon and Spill Gate Bay Walls

The siphon and outlet gate bay walls on the forebay side are in rough shape below the normal operating water level. The concrete surface is moderately to severely scaled. Some reinforcing is visible due to deterioration and some locations of vertical reinforcing are apparent due to concrete cracking likely due to corrosion. The upstream walls between siphon bays and gate bays are in poor condition and should be replaced (Figures 9-3 and 9-4). Strength of the concrete is adequate, but other issues have caused concrete deterioration and resulted in reinforcement corrosion.

Figure 9-3. Typical Divider Walls between Siphon Bays

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Figure 9-4. Typical Divider Walls between Spill Gate Bays

9.1.3 Left Training Wall

The left forebay training wall is the east side of the canal. The training wall is the canal bank and conforms to the canal bank side slope until it transitions to a vertical wall as it approaches the intake trash racks (Figure 9-5). The sloped portion of the concrete bank is generally cracked. There is also some evidence of voids behind the sloped portion of the concrete-lined bank, indicating the sidewall support is suspect (Figure 9-6). The concrete-lined sloped bank portion is in poor to fair shape. The vertical portion of the left training wall is in satisfactory condition with some minor surface scaling, shrinkage cracking, and concrete placement lift line visible (Figure 9-7). The identification of void areas behind the sloping concrete portion is concerning from a seepage standpoint.

Figure 9-5. Left Training Wall (East Canal Bank) Panoramic

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Figure 9-6. Left Training Wall Void (East Canal Bank) in Sloping Sidewall Portion (Rod is 6 Feet Long)

Figure 9-7. Left Training Wall (East Canal Bank) at Turbine Intake Area

9.1.4 Interior Training Wall

The interior training wall separates the turbine intake forebay from the siphon and spillgate bays and the Main Canal extension intake area. The wall has some shrinkage cracking, and an original lift line is visible.

Concrete surfaces have minor to moderate scaling, but overall element appears to be in satisfactory condition (Figures 9-8, 9-9, and 9-10).

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Figure 9-8. East Side of Interior Training Wall

Figure 9-9. Upstream End of Interior Training Wall

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Figure 9-10. West Side of Interior Training Wall

9.1.5 Right Training Wall

The interior training wall separates the turbine intake forebay from the siphon and spillgate bays and the Main Canal extension intake area. The wall has some shrinkage cracking and an original lift line is visible.

Concrete surfaces have minor to moderate scaling, but overall element appears to be in satisfactory condition (Figures 9-11, 9-12, and 9-13).

Figure 9-11. Right Training Wall (West Canal Bank) Panoramic

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Figure 9-12. Void Behind Right Training Wall Near to Electric Pumps (Rod is 6 Foot Long)

Figure 9-13. Right Training Wall Spalling and Honeycombing Near Electric Pump Location

9.1.6 Powerhouse Turbine Inlet Walls

The turbine inlet channel walls look in satisfactory condition. Original form board impressions are still visible. Some minor scaling of concrete surfaces observed (Figure 9-14). One location where presumed previous cracks were patched appears intact (Figure 9-15).

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Figure 9-14. Typical Turbine Intake Bay Wall Looking South

Figure 9-15. Evidence of Patched Crack on Turbine Intake Wall

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9.1.7 Powerhouse North Wall

The north wall of the powerhouse, for the purposes of this report, is a concrete wall between the pump floor of the pump house and the bottom of unreinforced brick. This height is approximately 11 feet 9 inches. The upstream side is water holding up to canal forebay operating water level. Some cracking with evidence of moisture leakage is apparent when the canal is operating (Figures 9-16 and 9-17). The concrete appears in fair condition. Cracks should be repaired.

Figure 9-16. North Wall Pumphouse Vertical Crack above Floor with Leakage

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Figure 9-17. North Wall of Pump House – Another Leakage Location

9.1.8 Main Extension Canal Inlet Walls

The Main Extension Canal walls have some cracking and general scaling of concrete surfaces below the operating water level. The lift line is visible on left side (south) wall (Figure 9-18). Concrete was intentionally excavated for the northerly pump bowl at the electric pumps (Figure 9-19). Walls downstream of the pump station discharge pipe encasement are shown in Figure 9-20. Walls are in fair condition

Figure 9-18. Left Side (South) of Main Extension Canal Intake

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Figure 9-19. Main Extension Canal and Electric Pump Station

Figure 9-20. Main Extension Canal Downstream of Pump Station Discharge Pipe Encasement

9.2 Forebay Floor

Forebay Floors include the following elements:

Inlet Screen Bays Floor Siphon and Outlet Gate Bays Floor Turbine Inlet Floor Electric Pumps Inlet Floor Area Main Extension Canal Inlet Area

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9.2.1 Inlet Screen Bays Floor

The screen intake forebay is in satisfactory condition. The floor is not original, but it is unknown how long ago it was replaced. Some shrinkage cracking is visible. Some surface scaling is occurring on top of slab.

Figures 9-21, 9-22, 9-23, and 9-24 show typical conditions of the floor area. Air content of sample taken from screen area floor is consistent with that required by the American Concrete Institute (2019) for freeze/thaw durability exposure of this area. A previous void area adjacent to the interior training wall was filled with concrete in years past as recollected by operations staff. Figure 9-21 provides the approximate location, which is painted on the interior training wall. The effectiveness of the void repair is not known.

Figure 9-21. East Side of Intake Screen Forebay Floor

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Figure 9-22. Interior East of Intake Screen Forebay Floor

Figure 9-23. Interior West of Intake Screen Forebay Floor

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Figure 9-24. West Side of Intake Screen Forebay Floor

9.2.2 Siphon and Spill Gate Bays Floor

The siphon and spill gate intake forebay is in good condition. The floor is not original, but it is unknown how long ago it was replaced. Some shrinkage cracking is visible. Typical condition is reflected in Figures 9-25, 9-26, and 9-27. Air content of sample taken from intake screen area floor is consistent with American Concrete Institute requirements (2019) for freeze/thaw durability exposure of this area.

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Figure 9-25. East Side of Siphon Bay and Spill Gate Bay Intake Forebay Floor

Figure 9-26. Interior of Siphon Bay and Spill Gate Bay Intake Forebay Floor

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Figure 9-27. West Side of Siphon Bay and Spill Gate Bay Intake Forebay Floor

9.2.3 Turbine Inlet Floor

The turbine inlet floor area is in satisfactory condition (Figure 9-28). Some surface scaling of concrete surfaces was apparent. One void was observed in the inlet channel floor in the most westerly turbine intake (Figure 9-29). The turbine intake floor has a drain opening that gets filled by a tapered concrete block during operations, but allows the area to drain to the turbine outlet floor when the canal is off line (Figure 9-30). This minimizes the freeze/thaw exposure to the turbine inlet bay floor and walls.

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Figure 9-28. Typical Turbine Inlet Floor Area Condition

Figure 9-29. Spall in Westerly Turbine Intake Channel Floor at Apparent Lift Line

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Figure 9-30. Drain Opening in Turbine Inlet Floor through to Turbine Outlet Bay

9.2.4 Electric Pumps Intake and Main Extension Canal Inlet Floor Area

The electric pumps intake and Main Extension Canal inlet floor area is in fair condition (Figure 9-31).

Some surface scaling of concrete surfaces exists. Several shrinkage cracks are apparent in the floor.

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Figure 9-31. Drain Opening in Turbine Inlet Floor through to Turbine Outlet Bay

9.3 Tailrace Walls

Tailrace walls include the following elements:

Turbine outlet walls West and south exterior pumphouse walls Siphon and gate bay divider walls Left training wall Interior training wall Right training wall Main extension canal walls

9.3.1 Turbine Outlet Walls

The turbine outlet walls are located spatially between turbine outlet bays in plan and vertically between the turbine outlet floor and the turbine inlet floor above. The impressions of the original form boards are still visible with minor loss of surface fines. The turbine outlet walls are in satisfactory condition (Figures 9-32 and 9-33).

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Figure 9-32. Typical Condition of Turbine Outlet Bay Walls from Tailrace

Figure 9-33. Typical Condition of Turbine Outlet Bay Walls and Concrete Shaping from Inside Outlet

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9.3.2 West and South Exterior Pumphouse Walls

The visible exterior of the west and south concrete walls of the pump house are in poor to fair shape (Figures 9-34 and 9-35). Cracking with moderate to heavy staining is evident. Lift lines in the concrete placement are also visible. Impressions of form boards from original placement are also generally visible.

Figure 9-34. West Exterior Wall of Pump House with Cracking and Staining Apparent

Figure 9-35. South Exterior Wall of Pump House with Cracking and Staining Apparent

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9.3.3 Siphon and Spill Gate Bay Divider Walls

Siphon and spill gate bay walls are in fair condition (Figures 9-36, 9-37, 9-38, and 9-39). General surface scaling below the water and splash levels was apparent.

Figure 9-36. Easterly Siphon Bay Walls

Figure 9-37. Westerly Siphon Bay Walls

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Figure 9-38. Easterly Spill Gate Bay Walls

Figure 9-39. Westerly Spill Gate Bay Walls

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9.3.4 Left Training Wall

The left training wall in the tailrace is in satisfactory condition adjacent to the pumping plant (Figure 9-40). As the cast-in-place concrete transitions to conform to the sloped sides of a trapezoidal section, the concrete is in failed to poor shape (Figure 9-41). A large bush is growing out of a hole in the concrete downstream of the vertical wall section. Farther downstream, the concrete lining is badly fractured and heaved and in extremely poor condition (Figure 9-42).

Figure 9-40. Left Canal Bank Wall Looking Downstream

Figure 9-41. Left Tailrace Training Wall Looking Upstream

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Figure 9-42. Left Canal Bank Armoring Looking Downstream

9.3.5 Interior Training Wall

The tailrace interior training wall is in good condition (Figure 9-43). The original form board impressions are generally visible. Minor scaling of surfaces below the high-water line. Lift lines are visible on the surface. Vertical dowels extend above the top of wall possibly an unfinished extension.

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Figure 9-43 Tailrace Interior Training Wall

9.3.6 Right Training Wall and Right Canal Bank

The tailrace right training wall is in poor condition. The original form board impressions are generally visible. Moderate scaling of surfaces are apparent below the high-water line. Cracking appears to be more extensive than expected for shrinkage cracking. Prominent spalling and exposed reinforcing on wall corner (Figure 9-44). The downstream right canal bank is composed of a section of riprap followed by another section of concrete rubble riprap. The riprapped bank wall looks to be in satisfactory condition (Figure 9-45). Seeps do come out of the riprapped canal bank for several days when the canal is drained.

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Figure 9-44. Tailrace Right Training Wall

Figure 9-45. Downstream Right Canal Bank

9.3.7 Main Extension Canal Walls

The Main Extension Canal walls are in generally satisfactory condition (Figures 9-46, 9-47, and 9-48).

Generally scaling of surfaces below operating water level is present. Some cracking and spalling is apparent.

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Figure 9-46. North Side of Main Extension Canal Under Discharge Pipe Encasement Looking Upstream

Figure 9-47. South Side of Main Extension Canal Under Discharge Pipe Encasement Looking Upstream

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Figure 9-48. North Side of Main Extension Canal Downstream of Discharge Pipe Encasement Looking Upstream

9.4 Tailrace Floors

Tailrace floors include the following elements:

Turbine outlet floor Turbine outlet tailrace slab Siphon and outlet gate bay discharge cells Siphon and outlet tailrace slab

9.4.1 Turbine Outlet Floor

The turbine outlet floor is in satisfactory condition. Light to medium scaling of the surface is apparent (Figure 9-49). The scaling in the tailrace floor is more severe.

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Figure 9-49. Typical Condition of Turbine Outlet Floor

9.4.2 Turbine Outlet Tailrace Slab

The turbine outlet floor is in poor to fair condition (Figure 9-50). Scaling is moderate to heavy. No reinforcing was observed. Air content of the petrographic analysis sample taken in the tailrace floor downstream of the turbine outlet indicate concrete was not properly air entrained for freeze/thaw resistance. Air content is in the 1% to 2% range.

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Figure 9-50. Typical Turbine Outlet Tailrace Slab Condition

9.4.3 Siphon and Outlet Gate Bate Discharge Cells

The siphon and outlet gate bay discharge cells are in generally fair condition where observed as shown in Figures 9-51, 9-52, 9-53, and 9-54. The cells are nominal 4 feet deep and partially filled with soil, gravel, and rock sediment as the downstream portion of the canal drains at the end of the season (Figure 9-55).

Material removal and pumping is required to observe anything below the tailrace canal invert. One spill gate bay was indicated to have a hole in the floor, but was not observed while concrete conditions were being assessed due to water and sediment levels.

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Figure 9-51. Easterly Siphon Bay Cell

Figure 9-52. Westerly Siphon Bay Cell

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Figure 9-53. Easterly Spill Gate Bay Cell

Figure 9-54. Westerly Spill Gate Bay Cell

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Figure 9-55. Debris in Spill Age Bay Cell

9.4.4 Siphon and Outlet Gate Bays Tailrace Slab

The siphon and spill gate bay tailrace slab is in generally serious condition (Figures 9-56 and 9-57).

Although, a specific petrographic sample was not taken in the floor downstream of the siphons and spill gates, it is anticipated to be similar to the tailrace concrete downstream of the turbine outlet bays. The severe scaling is indicative of concrete that is not adequately air entrained for freeze/thaw resistance.

Reinforcing is exposed in several areas in this section of the tailrace slab (Figure 9-58).

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Figure 9-56. East Side of Tailrace Downstream of Siphon Bays

Figure 9-57. West Side of Tailrace Downstream of Spill Gate Bays

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Figure 9-58. East Side of Tailrace Spalling/Scaling and Exposed Reinforcing Downstream of Siphon Bays

9.5 Elevated Concrete Elements

Tailrace walls include the following elements:

Discharge pipe encasement Pump house pump level floor Inlet bay top deck concrete beam Siphon and discharge bay top deck

9.5.1 Discharge Pipe Encasement

The discharge pipe encasement is in very poor condition (Figures 9-59, 9-60, 9-61, 9-63, and 9-64).

Concrete is obviously deteriorated with hammer sounding techniques indicating punky material. Stalactite formations exist on the underside of the elevated portions of the encasement Figure 9-65). Cracking and staining are prevalent on the sides of the pipe encasement. The top surfaces are very punky. The middle of the pipe encasement crossing the Main Extension Canal is badly cracked and vegetation is growing out of the cracks (Figure 9-62). The core samples taken for testing would not hold together. As a result, no strength testing could be done. One sample held together enough to be able to complete a petrographic test. Petrographic testing indicated the depth of carbonation was 2 inches and much deeper than other petrographic tested samples. Air content appeared to be in the 7% to 8% range according to the petrographers interpretation. ASR aggregate was not noted in the pipe encasement petrographic test. The Jacobs structural engineer anticipated that ASR would be found given the serious condition issues observed in the discharge pipe encasement concrete. The cause would require further investigation.

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Figure 9-59. South Side of Discharge Pipe Encasement over Siphon Bays

Figure 9-60. South Side of Discharge Pipe Encasement over Spill Gate Bays

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Figure 9-61. East Side of Discharge Pipe Encasement Span over Main Extension Canal

Figure 9-62. Top of Discharge Pipe Encasement Span over Main Extension Canal

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Figure 9-63. Top of Pipe Encasement and Top of Siphon Bays

Figure 9-64. Top of Pipe Encasement over Spill Gate Bays

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Figure 9-65. Stalactite Formations on Underside of Discharge Pipe Encasement

9.5.2 Pump House Pump Level Floor

The pump house floor has some cracking and staining. Cracking appears to be shrinkage cracking around floor pipe penetrations (Figure 9-66). Leakage likely occurs through the cracks.

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Figure 9-66. Pumphouse Floor Slab Shrinkage Cracking Condition

9.5.3 Inlet Bay Top Deck Concrete Beam

The concrete beam at the intake top deck appears to be in satisfactory condition with minor shrinkage cracking observed on the tops of beams. Figure 9-67 shows the top of the beam, which is shown on the bottom of figure.

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Figure 9-67. Pumphouse Inlet Bay Top Deck Concrete Beam Condition

9.5.4 Siphon and Discharge Bay Top Deck

The elevated deck over the siphon bays and over the most easterly spill gate bay is in poor condition.

Extensive pattern cracking is visible in the top surface. Spalling with exposed reinforced visible from the underside (Figures 9-68 and 9-69). The deck span over the most westerly spill gate was demolished and replaced at some point in the past. This section is in good condition (Figure 9-70).

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Figure 9-68. Top Deck over Most Westerly Gate Bays Replaced since Original Construction

Figure 9-69. Top Deck Underside Spalled and Exposed Reinforcing over Most Easterly Gate Bays

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Figure 9-70. Top Deck Underside Spalled and Exposed Reinforcing over Siphon Bay

10. Recommendations To achieve an additional 50-year life span for the concrete elements of the project, the following repairs and replacement, should be made:

Inject pump house floor and north wall cracks with epoxy

Demolish and replace discharge pipe encasement with new reinforced concrete

Replace tailrace slabs

Rehabilitate spill gate and siphon bays walls and top deck and include stainless steel plate armoring in the downstream discharge cells

Complete further investigations to ensure voids do not exist under concrete elements

Repair spalls on tailrace right side training wall

231005074011_bad7e8aa 50

11. References

American Concrete Institute (ACI). 2019. ACI 318-19 Building Code Requirements for Structural Concrete, Chapter 19.

Reapproved 2022.

Attachment 1 Drawings shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse shenriks Ellipse

Attachment 2 Crack and Defect Mapping

Attachment 3 Concrete Core Testing

GN Northern, Inc.

722 No. 16th Ave, Ste 31, Yakima, WA 98902

Revision #: 0 Page 1 of 1 Concrete Core Strength Testing Report

Client Project Name Tested by Date of Coring

Core Location Date of Break Length to Diameter

Core Length

(in) Core Dia (in) Area (in2) Max. Load

(pounds) Max (PSI) Correction Factor

FFC-2 1/24/2023 1.87 7.00 3.74 10.98 78,080 7,110 NA

FFC-3 1/24/2023 1.74 6.50 3.74 10.98 60,860 5,540 0.98

FFC-4 1/24/2023 2.00 7.50 3.74 10.98 71,681 6,530 NA

FFC-5 1/24/2023 2.00 7.50 3.74 10.98 77,060 7,020 NA

FFC-6 1/24/2023 2.00 7.50 3.74 10.98 59,420 5,410 NA

FWC-2 1/24/2023 1.73 6.50 3.74 10.98 44,660 4,070 0.98

FWC-3 1/24/2023 1.14 4.25 3.74 10.98 55,040 5,010 0.87

FWC-4 1/24/2023 1.94 7.25 3.74 10.98 41,320 3,760 NA

FWC-5 1/24/2023 1.54 5.75 3.74 10.98 45,660 4,160 0.96

FWC-6 1/24/2023 1.87 7.00 3.74 10.98 46,200 4,210 NA

TFC-2 1/24/2023 1.67 6.25 3.74 10.98 71,820 6,540 0.98

TFC-3 1/24/2023 1.80 6.75 3.74 10.98 81,360 7,410 NA

TFC-4 1/24/2023 1.80 6.75 3.74 10.98 52,120 4,750 NA

TFC-5 1/24/2023 1.40 5.25 3.74 10.98 59,600 5,430 0.96

TFC-6 1/24/2023 1.07 4.00 3.74 10.98 64,940 5,910 0.87

TWC-2 1/24/2023 2.00 7.50 3.74 10.98 75,000 6,830 NA

TWC-3 NA NA NA NA NA NA NA NA

TWC-4 1/24/2023 1.47 5.50 3.74 10.98 77,480 7,060 0.96

TWC-5 1/24/2023 1.07 4.00 3.74 10.98 76,980 7,010 0.87

TWC-6 1/24/2023 1.67 6.25 3.74 10.98 46,520 4,240 0.98

Remarks: (Note any deviations from standard, failing tests and notifications made) Core Tested in accordance with ASTM Standard: C42

1-17-23 & 1-18-23

FFC= Forebay Floor core FWC = Forebay Wall core TFC= Tailbay Floor core TWC= Tailbay Wall core

Core locations are shown on the Preliminary Concrete Deficiencies Exhibit sheets 2/10, 3/10 and 4/10 Core Sample TWC-3 has vertical fractures. All core samples obtaiend from discharge pipe encasement were broken in piecs

Jacobs - Boise, ID BIA Wapato Irrigation Project Drop 1 Pumping Plant Guy Vincent, CET- Materials Testing Manager

Attachment 4 Concrete Core Petrographic Analysis

PETROGRAPHIC SERVICES REPORT

WAPATO IRRIGATION PROJECT DROP 1 PUMPING STATION

SPILLWAY CONDITION INVESTIGATION

YAKIMA, WASHINGTON

STANDARD PRACTICE FOR PETROGRAPHIC EXAMINATION

OF HARDENED CONCRETE ASTM C 856-20

(CORES FFC-1, FWC-1, PEC-1, TFC-1 AND TWC-1)

Prepared for:

Ms. Rebecca Larsen GN Northern, Inc.

722 North 16th Avenue, Suite 31 Yakima, WA 98902

Prepared by:

Dominion Consulting, Inc.

2002 Linda Lane

La Grande, OR 97850

February 20, 2023 DCI Project No. 1121-1

Petrographic Examination of Concrete Products and Earth Materials

2002 Linda Lane, La Grande, OR 97850 dick@dominionconsulting.biz Tel: (541) 962-7430 Fax: (541) 962-7431

February 20, 2023

Ms. Rebecca Larsen Office Manager GN Northern, Inc.

722 North 16h Avenue, Suite 31 Yakima, WA 98902

Concrete Spillway Investigation Wapato Irrigation Project Drop 1 Pumping Station Located about 8 miles South of Yakima, Washington

Dear Rebecca, We received five concrete cores from you on January 30, 2023 reportedly taken from the referenced spillway project. You requested we determine the following:

1. Detailed description of concrete condition and composition.

2. Quality evaluation of concrete and concrete aggregates.

3. Air void system parameters including percent air contend.

4. Degree of cement hydration and estimates of water-cement ratio.

5. Cause and extent of deterioration.

6. Identification of physical quality problems including freezing and thawing damage.

7. Identification of finishing and workmanship problems.

8. Identification of deleterious materials such as alkali-silica gel or alkali-reaction glasses in aggregates.

9. Identification of any secondary reactions and products.

10. Carbonation depth.

In order to do this, we performed the applicable methods outlined in ASTM C856-20, Standard Practice for Petrographic Examination of Hardened Concrete, on all the cores.

Sample Preparation and Examination Methods

The cores were measured and photographed upon receipt and prepared for microscopic examination in accordance with ASTM C856-20. Cores as received and longitudinally sawn/polished surfaces were viewed with the unaided eye and a stereomicroscope (16-80X) to note overall aggregate and hardened paste characteristics.

2002 Linda Lane, La Grande, OR 97850 dick@dominionconsulting.biz Tel: (541) 962-7430 Fax: (541) 962-7431

Sample Preparation and Examination Methods (continued)

Thin-sections ground to 25 microns (less than 0.001 inch) were made from the uppermost and mid-depth 1½ inches of each core and studied using a polarizing microscope (50-400X) to observe degree of hydration, micro-cracking and any unusual features.

Carbonation (paste pH less than 9) was determined by applying Rainbow Indicator™, a phenolphalein-based solution, to freshly broken and sawn surfaces and comparing actual color changes to a standard pH color chart. Carbonation and ASR was also observed in thin-section analysis. Hardened paste was probed with steel dental tools to determine scratch hardness.

Discussion and Conclusion

The cored concretes contain well distributed basalt and sandstone gravel and crushed sand consisting of similar rock fragments, quartz and feldspar grains. Aggregate is clean and mostly sound with the exception of several sandstone particles in Core FWC-1 that show a low level of Alkali-Silica Reactivity (ASR) due to some reactive quartz grains in several sandstone particles.

The gel produced appears old and not reactive any more. The original expansive reaction only caused some local cracking of aggregate and paste.

Cores FWC-1 and TFC-1 do not appear to contain an entrained air-void system. We estimated their consolidation voids to range from one to three percent. Core PEC-1 did have an entrained system (7 to 8 percent), but many of the coarse particles are lined with voids. Concretes are only mildly leached. The deepest carbonated depth is present in Core PEC-1 at two inches and the deepest surface erosion is at least one inch on Core TFC-1. Refer to Table 1 in the Appendix for more details.

Our examination and testing results of the cored concretes indicate that they are in relatively good condition considering age and exposure conditions. However, our laboratory results should also be compared to observed field conditions (such as visual cracks, surface erosion, etc.) to have an overall understanding.

Tabulated testing results and laboratory photographs/photomicrographs of the cores are included in the Appendix. The above observations and comments specifically apply to the cores as received for examination and analysis. This report may be copied only in its entirety without prior written approval from this office. Remnants of the cores will be kept in our laboratory storage for three months than discarded unless notified.

2002 Linda Lane, La Grande, OR 97850 dick@dominionconsulting.biz Tel: (541) 962-7430 Fax: (541) 962-7431

Discussion and Conclusion (continued)

Please call (541) 962-7430 or email me at dick@dominionconsulting.biz if you have any questions concerning this report. We appreciate the opportunity to serve your petrographic needs.

Regards, Dick M. Glasheen, R.G.

President/Principal Petrographer

DCI Report No. 1121-1

APPENDIX

GN Northern Jobsite Picture

Dominion Consulting Lab Pictures

Table 1 – Lab Examination Details

2002 Linda Lane, La Grande, OR 97850 dick@dominionconsulting.biz Tel: (541) 962-7430 Fax: (541) 962-7431

Appendix – Wapato Irrigation Project (DCI #1121-1) Table 1 – Summary of Laboratory Examination

Item

Core FFC-1, #LN17054

8½” x 3-5/8” dia.

Core FWC-1, #171060

4¾” x 3-5/8” dia.

Core PEC-1, #LN171066

8½” x 3-5/8” dia.

As Received

Top is level with exposed sand; medium gray sides show well distributed aggregate, no prominent cracks or large voids; bottom is relatively flat with bonded crushed coarse sand.

Top is level with exposed sand & gravel;

medium gray sides show well distributed aggregate, no prominent cracks or large voids;

bottom is irregular broken-off with spots of white colored areas (old ASR gel deposits).

aggregate, no prominent cracks or large voids, fragment of a #6(?) rebar intercepted at 3½” below top (no rust corrosion); bottom is irregular broken-off with no fracturing of exposed gravel.

Aggregate

Coarse: Mostly basalt gravel with some sandstone, clean, well distributed; grading similar to ASTM C33 Size 57 (1”-#4) or Size 67 ( ¾”-#4).

Fine: Crushed, clean, well distributed similar rock fragments, quartz & feldspar grains.

Coarse: Similar to FFC-1, several sandstone particles contain reactive quartz (ASR);

grading similar to ASTM C33 Size 467 (1½”- #4).

Fine: Similar to FFC-1.

Coarse: Mostly basalt gravel with some sandstone, clean, well distributed; grading similar to ASTM C33 Size 467 (1½”-#4) or Size 357 (2”-#4).

Fine: Similar to FFC-1..

Paste

Medium gray; moderately firm scratch hardness; estimated air-voids 5-6%, well distributed; water drops rapidly absorbed;

relatively few micro-cracks; carbonated to ¼” (pH 8-9), deeper concrete pH 12-13; well hydrated portland cement, interpreted water to cement ratio 0.43-0.46; low degree of leaching.

Medium gray; moderately firm scratch hardness; estimated air-voids 2-3%, not air entrained; water drops rapidly absorbed;

moderate amount micro-cracks; carbonated to ¼” (pH 7-8), deeper concrete pH 10-11; well hydrated portland cement, interpreted water to cement ratio 0.42-0.45; low degree of

Medium gray; moderately firm with some soft spots; estimated air-voids 7-8%, well distributed, numerous voids around some coarse particles; water drops rapidly absorbed;

relatively few micro-cracks; carbonated to 2” (pH 6-7), deeper concrete pH 9-11; well hydrated portland cement, interpreted water to cement ratio 0.47-0.50; low degree of

2002 Linda Lane, La Grande, OR 97850 dick@dominionconsulting.biz Tel: (541) 962-7430 Fax: (541) 962-7431

Item

Core TFC-1, #171072

9” x 3-5/8” dia.

Core TWC-1, #LN171078

12½” x 3-5/8” dia.

As Received

Top mostly very dark gray (worn) with exposed sand & gravel, at least 1” loss of surface concrete; medium gray sides show well distributed aggregate, no prominent cracks or large voids; bottom is either broken-off or has bonded base rock sand & gravel.

aggregate, no prominent cracks or large voids;

bottom is irregular broken-off.

Aggregate

Coarse: Similar to FFC-1; grading similar to ASTM C33 Size 467 (1½”-#4) or Size 357 (2”-#4).

Coarse: Similar to FFC-1; grading similar to ASTM C33 Size 467 (1½”-#4) or Size 357 (2”-#4).

Paste

Medium gray; firm scratch hardness (including eroded top area); estimated air-voids 1-2%, not air entrained; water drops rapidly absorbed; some micro-cracks; not carbonated, top-2½” pH 9-10, deeper concrete pH 11-12; well hydrated portland cement, interpreted water to cement ratio 0.44-0.47;

low degree of leaching.

Medium gray; firm scratch hardness;

estimated air-voids 3½-4½%, well distributed;

water drops rapidly absorbed; some micro-cracks; carbonated to ¼” pH 5-6, deeper concrete 10-12 pH; well hydrated portland cement, interpreted water to cement ratio 0.47- 0.51; low degree of leaching.

FIGURE 1 Aerial view Wapato Irrigation Project Drop 1 Pumping Plant shows spillway (GN Northern Draft Report).

FIGURE 2 Side of Cores FWC-1, FFC-1 and PEC-1 as received for examination and analysis.

FIGURE 3 Opposite side of cores as received for examination and analysis.

FIGURE 4 Top of Cores FWC-1, FFC-1 and PEC-1 as received for examination and analysis.

FIGURE 5 Bottom of cores as received for examination and analysis.

FIGURE 6 Side of Cores TFC-1 & TWC-1 as received for examination and analysis.

FIGURE 7 Opposite side of cores as received for examination and analysis.

FIGURE 8 Top of Cores TFC-1 & TWC-1 as received for examination and analysis.

FIGURE 9 Bottom of cores as received for examination and analysis.

FIGURE 10 Sawed longitudinal surfaces show aggregate size, shape and distribution of the three labeled cores.

FIGURE 11 Sawed longitudinal surfaces show aggregate size, shape and distribution of the two labeled cores.

FIGURE 12 Micrograph of thin section shows typical appearance of basalt and sandstone particles and a consolidation void (V) (X50 polarized light).

FIGURE 13 More highly magnified micrograph shows typical appearance of cement hydration with relatively few un-hydrated portland cement grains (C). Some aggregates are labeled (A) (X400 plain light).

FIGURE 14 Micrograph of FWC-1 thin section shows ASR-created microcracks from a reactive sandstone (arrows). Some ASR gel is present in the larger crack (X50 partially polarized light).

FIGURE 15 More highly magnified micrograph of above reacted sandstone shows locally numerous microcracks inside the sandstone particle (arrows) (X100 plain light).