B1788 Storm Drain Design Analysis.pdf

Storm Drain System Redesign, Bldg 1788– IFB Submittal Table of Contents 23-162 Page i May 2024

TABLE OF CONTENTS

DESIGN ANALYSIS

1.0 GENERAL INFORMATION

A. PROJECT DESCRIPTION

B. EXISTING CONDITIONS

C. SITE SURVEY AND PIPE CLEANING/VIDEO

D. RATIONAL METHOD ANALYSIS OF STORMWATER

E. PIPE ANALYSIS

F. INELT ANALYSIS

G. STORMWATER EVALUATION SUMMARY

2.0 PROPOSED SOLUTIONS

A. GRAVITY DRAINAGE

1. Inlet Replacement

2. Pipe Replacement

3. Supplemental Pipe Installation

4. Roof Gutter Improvements

B. PUMPING OPTION

1. Courtyard Sump with Outlet Pipe

C. PROPOSED SOLUTION

3.0 ADDITIONAL COURTYARD IMPROVEMENTS

1. Joint Sealant and Masonry Sealing Improvements

4.0 COST ESTIMATES OF PROPOSED SOLUTIONS

Appendices

A – Calculations B – Statement of Work Clarification Meeting Notes Kick-Off Meeting Notes 35% Review Meeting Notes C – Cost Estimates

SPECIFICATIONS

SUBMITTAL SCHEDULE

DRAWINGS PROVIDED SEPARATELY AS FULL SIZE

Storm Drain System Redesign, Bldg 1788– IFB Submittal Design Analysis 23-162 Page 1

1.0 GENERAL INFORMATION

A. PROJECT DESCRIPTION

The following Investigation Report was prepared by TD&H Engineering and Cushing Terrell for Mountain Home AFB. This first step of the design process evaluates the existing shortfalls and provides potential solutions for the storm drain system serving the courtyard of Building 1788 at Mountain Home Air Force Base, Idaho.

This work is being completed to comply with the Scope of Work dated June 30, 2023, which is provided in Appendix B. Meeting notes clarifying and further refining government requirements for the work are in Appendix B.

B. EXISTING CONDITIONS

The project is in response to significant flooding of the courtyard and water damage to

Building 1788 during intense rain events. Figure 1.1 below is a photo of flooding that occurred on August 3rd of 2023. The event that caused the pictured flooding deposited a total of 0.73 inches of rain according to NOAA records for this 24 hour period, with most of the precipitation occurring during a short heavy storm event.

Figure 1.1: Flooded Courtyard (8/02/23)

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The existing storm drain that serves the courtyard includes a 6 inch diameter cast iron pipe that conveys flow to the west and under the building before daylighting to the concrete yard.

There is positive drainage outside of the facility that allows flow away from the building.

Site improvements in 2005 adjusted the outlet to accommodate the removal of sidewalk and the addition of a new building west of Building 1788. These changes replaced the end of the drainage pipe with 6” PVC pipe and adjusted the outfall location to the southeast by a few feet.

The courtyard has concrete flatwork with exposed aggregate finish, flatwork appears to be in good to fair condition. General observation revealed an ongoing water intrusion issue at the intersection of flatwork and sidewall condition. Sandbags are used to temporally prevent water from leaking into the building.

The exterior walls consist of concrete masonry units with vertical expansion joints at regular intervals. Mortar joints appear to be split or separated at some locations.

Figure 1.2: Courtyard Area.

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The main entry doors and windows consist of aluminum storefront framing. Joint sealants are missing or failing at several conditions, specifically around the window frames and at the door thresholds.

Figure 1.3: Cracked/Split Mortar Joints

Figure 1.4: Deteriorating Joint Sealants

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Pitched roofs are provided around the perimeter of the courtyard, the roofs consist of standing seam metal panels. There were no gutters and downspouts installed, as a result storm water from the roof drains directly to the ground.

Figure 1.6 provides excerpts from as-built plan sheets and notes developed during the review of the existing facility plans provided by the Base. The water from the roof sections facing the courtyard sheet flows to the edge of the roof and drains directly to the courtyard below, where runoff follows the slope of the hard surface to be collected in the drain. There are small diverters at the door openings which appear to function more as a snow stop, however, with the standing seam roof and the way the diverters are attached, rain will flow below them.

Figure 1.5: Missing Roof Gutters and Downspout

Original Bldg 1788 Plans

Bldg 1786 Site Plan Plans

Bldg 1786 Demo Plans

- Original plans show drain exiting at western curb line of sidewalk.

- With 6-inch Curb (152mm), outlet invert would be approximately 914.64.

- Plan invert is 915.03 at drain.

- Distance is approx. 133 feet from drain to outlet.

(0.86% Slope per Plans)

- Bldg 1786 Plans did not locate 6” drain pipe and clean out.

- Sidewalk where pipe outfalls was listed for demolition.

- New curb installed.

Figure 1.6 – Building 1788 and Building 1786 Plan Excerpts and Notes

Original Bldg 1788 Plans

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C. SITE SURVEY AND PIPE CLEANING/VIDEO

During the site survey work and cleaning/video of the pipe there was debris observed in and around the outlet end of the 6” pipe. This was cleared away. The cleaning contractor reported that the existing pipe had a significant accumulation of hardened sediment along the bottom of the pipe. This was cleaned on 10-18-23 and the video inspection showed a clean pipe after jetting. There is a short belly in the PVC pipe near the outfall with water and sediment collection indicating an area of negative drainage. The Video File is included as an attachment to this report.

The survey of the drainage pipe measured an elevation of 3001.84 at the invert of the inlet pipe in the courtyard and an elevation of 3000.94 at the outlet to the curb cut. The approximate length of the pipe is 133 feet. The current average slope of the pipe is 0.68 percent. The original plans provided that the design slope for the pipe was 0.86 percent.

The inlet cover for the drain line is a 12” by 12” cover shown below in Figure 1.7 below. A submittal for Smith Traffic Floor Drains with similar dimensions and openings listed the open area as 27 Square Inches for this drain.

D. RATIONAL METHOD ANALYSIS OF STORMWATER

The rational method was used to evaluate this basin that contributes to the floor drain in the center of the courtyard. Figure 1.8 shows the area that contributes to the floor drain.

The area is 0.22 Acres. The roof area is 0.18 acres, and the patio is 0.04 acres.

Figure 1.7: Courtyard Floor Drain

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A runoff coefficient of 0.95 was used as all areas are impermeable. Figure D.1 “Rainfall

Intensity, Duration and Frequency Relationship” from the 2019 Boise Stormwater Design

Manual provides 10 and 100 year rainfall intensities used to identify the peak rainfall as 1.8 inches per hour and 3.1 inches per hour, respectively. These intensities were discussed with Government Staff in a meeting held on Jan 29, 2024 and selected as the appropriate design intensities for this application. Appendix A includes the Rational Method

Calculations including the Time of Concentration calculations.

Using the Rational Method Equations for Peak Flow Q = CiA where C is the runoff coefficient, i is the rainfall intensity and A is the area in acres; Peak runoff was calculated as 0.38 cfs for the 10 year storm and 0.65 cfs for the 100 year storm.

E. PIPE ANALYSIS

Review of gravity flow in pipes determined the existing pipe capacity. Gravity flow is the preferred evaluation, as ponding and head above the inlet is not acceptable in the courtyard. The capacity of a 6 inch Cast Iron pipe with a slope of 0.68 percent and a length of 133 feet is approximately 0.47 cfs. Relative to the peak flows calculated above, the 0.47 cfs is less than the theoretical 0.65 cfs peak runoff calculated for a 100 year storm.

F. INLET ANALYSIS

The design of floor drain inlets in outdoor locations recommends that the open space of an inlet be equal to twice the cross sectional area of the connected drainpipe. As listed above, the open space on the existing floor inlet is 27 square inches, and the cross sectional area of the 6 inch pipe is approximately 28 square inches. This suggests that the inlet is too small for this application and the open space, while similar to the pipe cross sectional area, Figure 1.8: Contributing Roof and Courtyard Area.

23-162 Page 8 May 2024 allows much less flow through the grate than an open pipe due to the losses across the small openings.

G, STORMWATER EVALUATION SUMMARY

The existing pipe and floor drain are both undersized for the application. The pipe cleaning completed during the investigation will provide some additional capacity, but the drain and courtyard are still at risk of flooding during storms below a 100 year design intensity. The following section provides proposed solutions to address the current issues.

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2.0 PROPOSED SOLUTIONS

A. GRAVITY DRAINAGE

The current courtyard drainage system collects runoff from both the interior roof and courtyard. The first proposed solutions includes gravity drainage improvements options to better convey the stormwater outside the building to appropriate locations for runoff away from the facility.

1. Inlet Replacement

With any improvements, the existing floor drain in the courtyard is recommended for replacement with an inlet that will allow a minimum of 1.0 cfs of flow through the grate to provide a safety factor of 2.0 at the existing pipe location.

If only the inlet is replaced and no pipe improvements are provided, there will be no safety factor associated with the design as the 100 year storm may still exceed the flow capacity of the existing pipe during the peak flow period.

2. Pipe Replacement

As this is a closed location with no overflow locations available, a proposed replacement drainpipe will ideally have the capacity to convey the high intensities associated with a 100 year design storm with a safety factor. An 8- inch SDR 35

PVC pipe installed at the current grade would have the capacity of 1.5 cfs. This provides a 2.3 safety factor above 0.65 cfs estimated with a 3.1 in/hr intensity associated with the 100 year storm.

Replacement of the existing pipe would also require installation of a larger floor drain in the courtyard to increase the capacity of flow through the drain into the pipe.

Replacement of the existing pipe would require open trenching of the floors as well as coring larger holes in the interior and exterior wall footings. Trenchless technologies such as pipe bursting is not recommended due to the shallow location of the existing pipe.

3. Supplemental Pipe Installation

The minimum recommended pipe size for a new gravity pipe installation to drain the courtyard is 6 inches. A 6-inch pipe will provide an approximate additional 0.5 cfs for a total capacity of 1.0 cfs between the existing and new pipe. This provides a safety factor of 1.5 and capacity for intensities well above the 100 year design storm.

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Like the replacement option, the parallel pipes illustrated as option 3b in figure 2.1, would also require installation of a larger floor drain in the courtyard connected to each pipe.

If the supplemental pipe is connected directly to a new gutter system the head generated through the elevation of the downspouts will provide additional capacity through the pipe.

This installation would be completed by open trenching outside of the facility and in the courtyard with Horizontal Directional Drilling or an open cut through the floor slab to install the pipe under the building.

For the new pipe installation and gutter options proposed in the next section, the potential outfall locations of the gravity pipe have the same considerations for each concept. There were three discharge alignments identified that allowed gravity flow to positive drainage areas. Figure 2.1 provides the alignments (3a, 3b, and 3c) and outfall options and Figure 2.2 provides potential locations for installing new lines under the facility.

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4. Roof Gutter Improvements

(Option 1)

Improvements to the roof systems with a gutter and downspout collection system to collect runoff from the interior roof area and convey outside of the building would improve the function of the existing drain. The runoff from the patio area is under

0.43 cfs during the most intense storms and the existing 6” drain can accommodate this flow if the roof runoff were diverted from reaching the patio. Like the previous improvement options, the installation of a larger inlet drain is required in the courtyard to increase the capacity of flow through the drain into the existing pipe.

A gutter system would also drain through a pipe installed under the existing building from the courtyard to the exterior. This installation would be completed by open trenching outside of the facility and in the courtyard with Horizontal

Directional Drilling of the new line. The alignment options for the new drain line leaving the building are shown in Figures 2.1 and 2.2.

If piping cannot be installed by horizontal boring due to invert issues, it would require piping to be installed through the interior of the building via manual labor and patch and repair of interior slab on grade and associated finishes.

Based on the rainfall runoff of the roof from the most intense storm, a gutter sized to 5 inch diameter (4 inch x 5 inch minimum area) on the short roof sides of the courtyard and 7 inch diameter (7 inch x 6 inch minimum area) on the long roof sides of the courtyard. The downspouts sized to 4x4 at end point of the sloped gutter(s) required to collect the rainfall.

Utilizing a gutter sizing program for the gutters and downspouts based on local rainfall of 2 inch rainfall per hour with gutter installed level.

Areas considered:

Two long sides: Ea 2915 SF (271 SM) (2) = 5830 SF (543 SM) Add high hip one side Ea 720 SF (67 SM) 720 SF (67 SM) Two Short sides: Ea 632.5 SF (58 SM) (2) = 1265 SF (116 SM)

TOTAL 7815 SF (726 SM)

Total square footage of area drained 7815 SF (726 SM)

Gutters can be a 6 inch wide by 6 inch deep gutter and run dead flat. Gutters would discharge to a 4 inch x 4 inch (10 cm x 10 CM) downspouts in each long and short gutter section. Each downspout will connect to a boot section to accommodate the 4 inch x 4 inch gutter and thus connected to a 4 inch (10 CM) line below grade sloped at 1/8 inch per foot. The lines from the downspouts would connect to a 6 inch (15 CM) line sloped at 1/8 inch per foot to carry the discharge as collected from the gutters. The 6 inch (15 CM) can carry 10,700 SF (994 SM) of collected area.

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Provide heat tape at all gutters and downspouts to prevent drainage issues associated with ice damming in the winter months.

Option 2)

During the 35% design review discussion, the Government directed the design team to remove the roof gutter and downspout collection system due to budgetary concerns. As an alternative, the Government opted to install 10’-0” gutter segments at the entry doors.

B. PUMPING OPTION

To accommodate additional flow through existing or smaller pipes, pumping was evaluated in the review of potential solutions.

1. Courtyard Sump with Outlet Pipe

This option envisions construction of a sump well in the courtyard and installation of a pump that can convey the 100 year storm flow of 0.65 cfs. This will require a pump capable of around 300 gpm to provide a 1.5 safety factor and would need a variable frequency drive (VFD) to operate at a much lower flow rate during smaller, more frequent storms.

One method to simplify the pumping system would be to use the existing gravity drainage system for most storms and have the pumping system designed to operate when the gravity system is overwhelmed. This pump could be smaller but would still require approximately 115 gpm at peak flow to prevent flooding and provide a 1.5 safety factor.

Both options would likely require VFDs to avoid requiring the large sump volume needed to collect enough water to allow constant pumping rates at full speeds.

A 4 inch line can be installed through the existing drainpipe but may be undersized for the largest storm and pumping requirement.

A 6 inch pipe can be installed parallel to the existing line similar to the gravity drainpipe proposed above, or above grade through the building.

The pump options will require maintenance and operation of a larger pump and control system and will be susceptible to failure during power outages that can accompany heavy storms.

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Piping through the building from an exterior collection point into the building has the potential to have leaks in the piping system and thus damage finishes within the building. Maintenance concerns are also potential during freeze thaw cycles where during a freezing period the exterior portion freezes up and then immediate thaw happens, and the system can only accommodate what has been thawed to pump through the building.

C. PROPOSED SOLUTION

After presenting the preliminary options to the Base and receiving their feedback, the design team is moving forward with the proposed solution presented in the 95% design plans submitted with this report and includes the following tasks:

• Installation of short gutter sections located above the two access locations to the courtyard.

• Removal and replacement of door frames to allow construction access to courtyard.

• Protection of indoor spaces necessary for construction access to courtyard.

• Installation of larger outdoor floor trench drain in the courtyard.

• Replacement of concrete to provide positive drainage in courtyard to the new area drain.

• Restoration of disturbed areas

• Repair failed/missing joint sealant and masonry sealant in courtyard.

These proposed repairs were the basis for the development of the 95 % design submittal set.

The decision to not include additional drainage pipe in the scope was made at the stormwater design criteria follow up meeting held after the 35 percent review meeting on

January 29th, 2024. Government staff provided feedback that the design was acceptable accounting for the maximum potential runoff generated from rainfall intensities associated with the Boise Storm Drain Manual 100 year storm values. There is the potential that storm intensities may overwhelm the pipe capacity during the heaviest rainfall associated with a 100 year storm, but the Government was comfortable with the risk associated with only increasing the inlet capacity and not adding additional pipe capacity with this project.

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3.0 ADDITIONAL COURTYARD IMPROVEMENTS

A. Joint Sealant and Masonry Sealing Improvements.

Replacement / repair of failed/missing joint sealant where flatwork intersects the exterior sidewalls shall be considered. Replacement / repair of failed/missing sealant around aluminum storefront framing and window opening framing shall be considered. Repair cracked/split mortar joints at all the exterior sidewall conditions that face the courtyard with a silicone based sealant and added sand mix to make appearance look like mortar.

Given the current masonry veneer being a split face colored concrete block, the material is susceptible to taking on moisture because of the concrete material and the process utilized to manufacture the split face concrete block. The overall finished block is a porous material and thus should be regularly maintained every 5 to 10 years with a sealer / water repelling product. It is recommended that the masonry be cleaned, and a clear siloxane based cold applied waterproofing / water repelling penetrating masonry sealer is recommended to be applied over all masonry surfaces facing the courtyard. Application of this will resist water penetration from wind driven rain from entering the wall cavity construction.

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4.0 COST ESTIMATES OF PROPOSED SOLUTIONS

The scope of work does not identify a Maximum Construction Cost (MCC). Costs as presented herein are estimates based on the current level of design for the direction and potential solution discussed and to be continued further development during the preliminary reporting meeting.

The total estimated cost of the project as defined at the 95% design stage is $140,000.

The complete cost estimate is provided in Appendix C.

APPENDIX A

CALCULATIONS

Subdivision Name MHAFB Bldg 1788

County 0.95 Location

Lot/Area No.

Intensity Values Q=C*i*A 10 year 1.8 inches/hr @ ToC 10 min

100 year 3.1 inches/hr @ ToC 10 min

= input field

Roof 0.18 acres 7633 ft3 Q= 0.300 ft3/sec Patio 0.04 acres 1950 ft3 Q= 0.077 ft3/sec Total 0.22 acres 9583 ft3 Q= 0.376 ft3/sec

Roof 0.18 acres 7633 ft3 Q= 0.516 ft3/sec Patio 0.04 acres 1950 ft3 Q= 0.132 ft3/sec Total 0.22 acres 9583 ft3 Q= 0.648 ft3/sec

100 year Peak Release Flow Rate Courtyard (flow rate)

Rational Method Co-Efficients (C) Paved/hard surfaces

Mountain Home AFB

10 year Peak Release Flow Rate (flow rate)Courtyard

2019 Boise Stormwater Design Manual D-1

APPENDIX D

Hydrologic and Hydraulic Graphs

Figure D.1 rainFall intenSity, Duration anD FrequenCy relationShiP

Courtney N. Lyerly Line

Courtney N. Lyerly Line

Courtney N. Lyerly Text Box

3.1 in/hr

Courtney N. Lyerly Text Box

1.8 in/hr

Courtney N. Lyerly Rectangle

APPENDIX B

STATEMENT OF WORK

CLARIFICATION MEETING NOTES

KICK-OFF MEETING NOTES

35% REVIEW MEETING NOTES

STATEMENT OF WORK

PROJECT QYZH 230009

STORM DRAIN SYSTEM REDESIGN, BLDG 1788

MOUNTAIN HOME AIR FORCE BASE, ID

30 JUNE 2023

This statement of work (SOW) defines requirements for A-E services to provide civil-engineering design to redesign the storm drain system for Building 1788, at Mountain Home AFB, ID, AF Project QYZH 230009.

In carrying out the work assignment issued in this task order (TO), the Contractor shall furnish the personnel, services, equipment, materials, facilities, and other requirements necessary for, or incidental to, the performance of work set forth herein.

Primary technical services will be performed by individuals who are credentialed members of architectural, science, and engineering professions. The credentialed professional(s) (a) will be licensed (e.g., registered professional engineer) to practice in the state where the facility is located and (b) commands the necessary expertise, in terms of knowledge and experience, to undertake the specified task.

PROJECT HISTORY

Due to an unusually high level of precipitation in the last year, the storm drain system for Building 1788 was unable to provide enough drainage, resulting in significant flooding and damage to the facility.

Specifically, a backed-up courtyard drain resulted in $350,000 worth of standing water damage throughout the first floor of the facility including walls and carpet.

A. SCOPE

The Contractor shall provide investigative and design services required to diagnose the current shortfalls of and subsequently replace the storm drain system in Building 1788, at Mountain Home AFB, ID, AF Project Number QYZH 230009. The design services shall include all related and supporting A-E disciplines that are typical for storm water drain design, and within an industrial building environment, such as mechanical, and any other disciplines that are required to provide a full design. Design and review shall proceed by providing, 35%, 95%, and 100% design submittals. The general intent of the design is as follows:

1. As-Built Drawings: These will be provided for Building 1788 for reference only, field verification required.

2. Facility Use during Construction: Building 1788 is to be occupied during construction.

Contractor shall provide safety barriers for military personnel and necessary temporary restroom facilities while restrooms are under construction. In addition, there will be a few instances where the building occupants (726th Air Control Squadron personnel) will need the ability to schedule (ahead of time) periods where construction crews are temporarily not allowed within and around Building 1788.

Project: QYZH 230009 - Bldg 1788 Storm Drain Redesign and Replacement

3. Material salvage and recycling: All non-hazardous material should be recycled as much as possible. MHAFB has a recycling program and the Point of Contact is: Michael Wussow, Solid Waste Program Manager, 208-828-6667.

4. Building Utilities: All required utilities shall be connected to the existing infrastructure.

5. Design Period of Performance (POP): The Design POP shall be 123 calendar days. The AE shall provide a detailed schedule showing how the Design POP shall be met.

B. DESIGN SUBMITTAL REQUIREMNTS

1. Kick-Off Mtg: The AE shall convene and facilitate a design kick-off meeting with stake holders to discuss project objectives, steps for completion, and gain any additional design inputs and or clarifications from the CES project manager, users, and all involved base agencies. Additionally, the AE shall conduct site survey(s), as required, to gather information to verify existing conditions.

2. Submittals:

a. 35% Design:

i. Plans and Specifications: develop to 35% design drawings that include, but are not limited to:

1. Layout drawings

2. Identify all demolition work and all new construction

3. Provide all schedules and details required

4. Contractor haul route and staging areas

5. Provide specifications as required to address all areas of work involved

6. Provide schedule of submittals

ii. Design Analysis: The design analysis shall be revised should the basis of the design change.

iii. Cost Estimate: Provide a construction cost estimate at the 35% design submittal stage;

include an estimated construction duration time for the project

iv. Review: MHAFB will review the submittal and provide comments. This will be followed by an in-person review meeting to discuss comments and resolutions.

b. 95% Design

i. Plans and Specifications: Incorporate all comments from the 35% design and develop to 95% design drawings that include, but are not limited to:

1. Layout drawings

2. Identify all demolition work and all new construction

3. Provide all schedules and details as required

4. Contractor haul route and staging areas

5. Provide complete specifications as required to address all areas of work involved

6. Provide schedule of submittals

ii. Design Analysis: The design analysis shall not be changed unless the basis of design is substantially changed

iii. Cost Estimate: Provide a construction cost estimate at the 95% design submittal stage;

include an estimated construction duration time for the project

iv. Review: MHAFB will review the submittal and provide comments. This will be followed by an in-person review meeting to discuss comments and resolutions.

c. 100% Design

i. Plans and Specifications: Incorporate all comments from the 95% design and develop to 100% design, construction bid solicitation will most likely occur next Fiscal Year.

This shall include, but is not limited to:

1. Layout drawings

2. Identify all demolition work and all new construction

3. Provide all schedules and details as required

4. Contractor haul route and staging areas

5. Provide complete specifications as required to address all areas of work involved

6. Provide schedule of submittals

ii. Design Analysis: The design analysis shall not be changed unless the basis of design is substantially changed

iii. Cost Estimate: Provide a final construction cost estimate at the 100% design submittal stage; include an estimated construction duration time for the project

iv. Review: MHAFB will back-check the 100% design submittal to ensure all 95% design submittal comments have been incorporated.

v. All documents are to be signed, sealed, and dated by the AE.

d. 100% Final Design: In the event that there are any comments from the 95% design submittal that were not incorporated or errors are discovered, MHAFB reserves the right to require an additional 100% design submittal. All materials that require revisions shall be resubmitted.

3. Submittal Review. The AE is responsible for the resolution and incorporation of Government comments into the project design. At each submittal, within the Design Analysis, address previous review comments. If the comment was incorporated into the design, a response shall so indicate. If the comment was not incorporated, an explanation shall be provided for not doing so.

Contact the Government reviewer to discuss any comment that will not be incorporated, for whatever reason.

The AE is responsible for providing responses to all comments, noting either the intent to incorporate the comment’s direction or the AE’s exception to any comments. Provide for every exception a brief but specific explanation of the exception. If the comment requires action other than that recommended in the comment, note the intended alternative action. No direction must be construed from comments. The AE must provide a design compliant with code, in schedule, and within design scope.

4. Submittal Schedule and Requirements: The schedule for delivery of Final Documents is in calendar days after Notice to Proceed.

Submittal Schedule

REQUIREMENT TIME ALLOTTED

PER TASK

RUNNING TOTAL

1 Design Submittal, 35% 21 21 2 Government Review, 35% 14 35 3 Design Review Meeting 2 37 4 Design Submittal, 95% 21 58 5 Government Review, 95% 14 72 6 Design Review Meeting 2 74 7 Design Submittal, 100% 21 95 8 Government Back check 7 102 9 Final 21 123

5. Preparation of Drawings. Provide two copies of bound drawings on 11”x17” paper, and approved electronic media for all submittals. Prepare drawings as described under each phase of the design. Produce drawings using Computer Aided Design and Drafting (CADD) software.

Provide drawings in both CADD (compatible with installation users) and Adobe Acrobat Portable Document Format (PDF) files for design and record drawing submittals.

6. Preparation of Specifications and Reports. Provide two sets of bound specifications and reports on 8-1/2”x11” paper for the Final submittal only. All other submittal specifications and reports will use approved electronic media. Specifications are to be as concise as possible, definitive, and free of ambiguities and omissions that may result in controversy and Contractor claims for additional compensation. Specifications are to cover all aspects of the project.

7. Preparation and Content of Design Analyses. Provide bound design analysis on 8-1/2" x 11" paper and on approved electronic media. Provide a cover sheet identifying the documents including the submittal stage, project title, location, base project number, solicitation number, AE firm name, and date. The design analyses shall include three parts, a basis of design, design calculations, and design decision documentation.

The basis of design is a narrative description of the key elements and features of the design. The narrative outlines facts sufficiently complete to demonstrate that the project concept is fully understood and that subsequent design details and their ultimate presentation in the final drawings and specifications will be based on sound architectural and engineering decisions. Provide a discussion and description of the design in each of the technical disciplines relevant to the project.

The design calculations are information, justification, and calculations necessary to verify the design in each of the technical disciplines relevant to the project. Include catalog cuts of proposed products used as a basis of design, where applicable. Computer outputs shall be properly identified and appropriately referenced as to the program name, version and source.

The design decision documentation section includes design instructions, conference call records, meeting minutes, design review comments, and related information used to drive design decision making.

C. TECHNICAL CRITERIA AND STANDARDS

Use of Unified Facilities Guide Specifications (UFGS) within the SpecsIntact software is mandatory. It is free and can be obtained at: https://specsintact.ksc.nasa.gov/Software/Software.shtml. UFGS are available at the Whole Building Design Guide website (http://www.wbdg.org/). Modify and edit to reflect the latest proven technology, materials, and methods, if warranted. If UFGS is not available, then develop specification using UFGS format and numbered in accordance with Construction Specifications Institute (CSI) current format for construction activities.

The design shall comply with the following technical criteria and standards (utilizing the most current editions):

UFC 1-200-01 DoD Building Code UFC 3-101-01 Architecture UFC 3-201-01 Civil Engineering UFGS 33 40 00 Stormwater Utilities UFGS 33 46 13 Foundation Drainage 366 CES GIS Deliverables Final AEC CAD Standard 6.1 (USACE) Section 01 57 19 Temporary Environmental Controls MHAFB 20220614

D. GENERAL PROVISIONS

1. Work Authorization: Any work performed without being directed to do so, in writing, by the Contracting Officer will be done at the AE’s risk.

2. Confidentiality: Quantity surveys and cost estimates shall remain the sole property of the Government and shall not be made available to others for any purpose.

3. Distribution Schedule:

Submittal Number of Copies Hard Digital

35% Design 2 (11x17) 2 95% Design 2 (11x17) 2 100% Design 2 (11x17) 2 Final Design For Construction 2 (22x34) 2

E. SPECIAL CONDITIONS

1. Execution of the Work: The AE shall furnish sufficient technical supervisory and administrative personnel to ensure execution of the work in accordance with the delivery schedule. The AE shall be responsible for checking calculations, drawings, details, notes, and other work products to verify the design intent, technical adequacy and scope of work have been fulfilled.

2. Project Management: The AE shall assign an individual to serve as a single point of contact between the AE and the Government for all services required under this task order.

3. Building Access: Access to Building 1788 during Design or Construction will require escorted access. Coordinate with Civil Engineering Squadron Project Manager Ryan Ziegler at email:

ryan.ziegler.4@us.af.mil or call: 208-828-2735 (o), 619-313-7759 (c).

4. Conferences and Meetings:

a. Conduct all meetings and conferences pertinent to the services under this task order as directed by the Government, to include chairing all meetings and managing meeting time effectively.

b. Meetings other than those stated herein, may be held whenever requested by the Government for discussion of questions and problems relating to the services required under this task order.

5. Submittal Instructions: Send all submittals to:

366 FAS/PKB

366 Gunfighter Avenue, Suite 498 Mountain Home AFB, ID 83648

4 0 6 . 7 6 1 . 3 0 1 0 t d h e n g i n e e r i n g . c o m

1 8 0 0 R i v e r D r i v e N o r t h

G r e a t F a l l s , MT 5 9 4 0 1

MEETING NOTES

Date: August 7, 2023 Time: 10:00 AM

Present: TD&H:

John Juras Nate Young Cushing Terrell, Subconsultant John Bolton

Mountain Home AFB Lt Ryan Ziegler – MHAFB CES PM Sgt Jeremiah Burns – MHAFB Contracting

Subject: Scope Clarifications Meeting

TDH

Job No.:

Project Name: A&E – Storm Drain System Redesign, B1788 at MHAFB, ID; Project No

QYZH-01788

Discussion Items:

1. As-built drawings B1788

a. Lt Zeigler is working on getting CAD on his computer and will work through drawings to determine which as-builts are appropriate and send over. He will visit the site to see recent damage and get pictures and better understanding of issues.

b. John Bolton – Key plans – Floor plan, roof plan, building sections, plumbing, underground is key, roof drain sizing

c. John Juras – If you can get us the full building as-built plan set that would help.

d. Lt Zeigler will get us what we need this week

2. Basis of Design Reports

a. Should be a report that states how design was looked at and if we can get that it will help us scope the work better. Without it we will have to reinvent the wheel.

3. Geotech Report

a. John shared his screen to show floor plan layout for B1788 and Geotech

Report

b. Borings show bedrock at 10 feet which shouldn’t be a problem

c. Sandy silty material with cementitious minerals which show hydraulic conductivity near zero.

4. Utilities

a. We created a GIS utility map that shows utilities which seem to indicate culverts along Bomber Street

b. We are hoping to get a regional stormwater report on the adjacent conveyance ditches, etc.

August 7, 2023 PAGE NO. 2

c. Courtyard of B1788 has been the biggest issue.

5. Incident report

a. Most severe damage on eastern side and area around the courtyard.

b. Western and northern part of the building is less severe.

6. Scope of Work

a. Are there any architectural issues or construction that are needed?

i. Lt Zeigler clarified that the cleanup activities and remediation have occurred to repair the damage and the scope is to identify the drain issues

ii. Should we be looking at ways to improve the building system? At this time no, but after Lt Zeigler talks with facility personnel, if that is warranted a new SOW may need to be issued.

b. Should we be focusing only on the courtyard area only or the entire area around the building

i. Lt Zeigler mentioned he would get clarification

c. Roof plan should show if there are issues with roof drainage

d. John Juras mentioned that we would get a televising contractor on board to camera the courtyard line.

e. Mechanical

i. May involve upsizing of pipes, pump system, installation of roof drain leaders, etc.

f. John clarified we would not need any additional Geotech field work. We may have our Geotech provide some infiltration recommendations.

g. John asked if there are any times where survey crew could not enter building

i. Lt Zeigler would coordinate scheduling of survey crew and will let us know if there are any concerns or times for the crew to get access.

h. Radar or similar in the area has some radiation that interferes with survey

i. Lt Zeigler will coordinate when there are down times to accommodate the survey.

i. Specifications

i. SpecsIntact has been what we have been using for specs and we assume that is what we will use on this project as well.

ii. Submit specs list at 35% and full specs at 95%. Receive comments at

95% to incorporate at 100%. Leaves a large gap from outline to final project

1. Lt Zeigler will get some clarification to whether a 35, 65, 95, 100 type of submittal.

2. John - Maybe we wait to do detailed specs until after 95% and then get comments worked into 100 with a second 100 submittal back check if needed.

j. Schedule

i. John Juras – We will get a camera crew out to survey which takes some time to accommodate

1. John and John B both thought we should extend 35% time from 21 days to 45 days.

a. Lt Zeigler would confirm that is acceptable

2. We could shorten 100% from 3 weeks to 2 weeks.

3. John B thought we should also add some time to 95% time, go from 21 days to 35 days

4. Each deliverable stage will have electronic submittals with hard copies provided at final deliverable.

August 7, 2023 PAGE NO. 3

Additionally, we discussed:

1. We have been sending docs to contracting and they have gotten stuck there, should we maybe also do a DOD SAFE submittal to Lt Zeigler? We will do both.

2. If we get all of the needed information this week, we could get scope and fee out by the end of next week.

End of Meeting Notes

MONTANA | WASHINGTON | IDAHO | NORTH DAKOTA | PENNSYLVANIA

t d h e n g i n e e r i n g . c o m

Date: 08/31/2023 Time: 10:00 AM

Present: Jeremiah Burns – MHAFB -

Contracting

Lt Ryan Ziegler – MHAFB - Project

Manager

SSgt Kelvin Shaw – MHAFB –

Building User

Charity Mecham – MHAFB

John Juras – TD&H

Jana Cooper – TD&H

Courtney Lyerly – TD&H

Alfonso Ramirez – CT

John Bolton – CT

Laura Rankin – CT

Subject:

Storm Drain System Redesign, Building 1788 – Kick-off Meeting

TDH

23-162

• Introduction/Attendance

• Review Clarification Notes o Noted that a portion of the storm drain may run under an adjacent building

(Bldg 1786) that was built after storm drain, or mechanical yard southwest of building not shown on design drawings o John noted that Design Team will be requesting locates for survey and do a site visit in the near future

▪ Survey visit to coordinate with facility contact (SSgt Shaw) for access during radar down time to prevent impact to survey equipment.

o Existing As-Builts were not up to date – new information was sent to John, but TD&H has not have time to review prior to this meeting o John noted that TD&H intends to have contractor televise the Storm Drain line; need access to the building o CT site visit and timing – John B – not yet for timing, want to verify items listed in the coordination meeting; including roof drains that don’t have gutters, causing water to hit foundation – verify courtyard area; review plumbing, etc., if a pump system is needed want to understand configuration of the rooms and where that could be located o Challenge Assumptions

▪ Assume drain has an outlet somewhere that we can enhance ability of water to leave outlet

▪ Courtyard – Current grades contribute to water issues as they don’t properly drain to inlet.

August 31, 2023 PAGE NO. 2

▪ Not a lot of drop from floor elevation and drain that leaves the building

– line itself is flatter than desired minimal standard and has very little cover outside of the building – are there any freezing issues??

• Gov – could be potential issue; Lt Shaw has not seen issue with freezing in that area

• Existing trees have been removed, not sure about root systems

▪ Access into building from outside to courtyard for construction efforts

(equipment, etc.) there is only a regular doorway – single door, halls are not carpet

▪ There has been water damage (outside our scope of work) last year there was a remediation project to replace drylwall, etc.

o Use of Courtyard

▪ Really no current use for the courtyard, sandbags positioned to keep water out of facility.

▪ Future use could be for relaxation, or more use, but it’s not necessary

▪ Base HVAC mentioned idea of moving mechanical room to courtyard.

o TD&H to update schedule with today’s date as the NTP and review meeting.

(Schedule Included Below)

• Next Steps o Design Team to review all materials o Gov to provide any other as-builts they can find o Dig Permit and Site visit scheduling to ensure base access/processing

MONTANA | WASHINGTON | IDAHO | NORTH DAKOTA | PENNSYLVANIA

t d h e n g i n e e r i n g . c o m

Date: 1/22/2024 Time: 1:00 PM

Present: Lt Ryan Ziegler – MHAFB - Project Manager Brad Newcomb – MHAFB Martin Ray – MHAFB Cory Mikita - MHAFB

John Juras – TD&H Courtney Lyerly – TD&H Alfonso Ramirez – CT John Bolton – CT Laura Rankin – CT

Subject:

Storm Drain System Redesign, Building 1788 – 35% Review Meeting

TDH

23-162

Introduction/Attendance 35% Review Comment Discussion (35% Submittal Review Comments are attached to these meeting notes) o Many of the review comments (Items 1, 3, 4, 5, 6, 9, 10, & 11) were on the

Hydrology methods used for the calculation of rainfall intensities used in the 35% report. Review comments highlighted discrepancies in the methods and values used for the alternatives design.

o After discussion of appropriate methods for design of the small area drainage, TD&H were directed to use the Boise Hydrology Manual and rational method to develop the 100 year design storm peak intensity required for drainage from the courtyard. (The design manual was provided by Brad Newcomb after the meeting). Appropriate safety factor will be identified and included with design.

o Inlet failure was highlighted as a cause of the past flooding. A request was provided for two drop inlet locations in the courtyard to provide redundancy.

o The concern of drainage toward the building was provided with the request to regrade courtyard to inlets away from building (currently included in plans).

o Direction was provided to remove full gutters and only provide short gutter sections over the two door locations. Gutter to spill to one side of doorway with no downspouts. Gutter to be at least 1/8” per foot slope.

o Suggestion provided to replace the short section of existing drain pipe from the cleanout outside of the building to outfall to remove dip at the end of the pipe. This will be added to the project.

o Preferred drawing page size border style will be provided by LT Ziegler for next submittal format.

Next Steps

January 22, 2024

PAGE NO. 2

o Design Team to address comments and incorporate into the 95% Submittal plan set. Comment Responses returned in Table at 95% Design Submittal on Feb 21.

o Gov to provide preference on Border Style and Page size.

o TD&H to provide updated storm water calculation based on Boise Design

Manual to confirm peak rainfall intensity and determine if an additional drainage pipe is required ahead of 95% Design.

APPENDIX C

COST ESTIMATE

Description Quantity Unit Unit Cost Cost

Mobilization 1 EA $5,000 $5,000 Salvage and Replace Landscaping Rock Mulch 1 LS $250 $250 6" Drainage Pipe, Including Fittings 35 LF $100 $3,500 Concrete Remove and Replace 4" Thickness (Courtyard and Sidewalk Repair)

1,557 SF $28 $43,596

Remove and Replace Floor Drain 1 EA $4,500 $4,500

General 1 LS $6,612 $6,612 Masonry 1 LS $14,264 $14,264 Wood, Plastics Composites 1 LS $5,410 $5,410 Thermal and Moisture Protection 1 LS $14,369 $14,369 Openings 1 LS $1,271 $1,271 Finishes 1 LS $1,453 $1,453 Electronic Safety and Security 1 LS $727 $727

Subtotal $100,952 Contingency (10% of Subtotal) $10,095

Subtotal $111,047 OH, Profit, Inflation, Bonds, Taxes, Ins. (27.5%) $30,538

Rounded Total Construction Estimate $142,000

Budgeting Cost Estimate (IFB) Building 1788 Storm Drain

Civil Items

Architectural Items