Attachment 17 - APPNDX_B-Drainage_Rprt-VA_CT_West_Haven_EHRM_IU-689-22-700.pdf

APPENDIX B – DRAINAGE REPORT

EHRM INFRASTRUCTURE UPDGRADE DESIGN

VA Healthcare System, West Haven, CT 06513

Project #: 689-22-700

APPENDIX B – DRAINAGE REPORT

DRAINAGE REPORT

100% SUBMITTAL

VA WEST HAVEN EHRM PROJECT

BUILDING 41

VAMC, WEST HAVEN, CONNECTICUT

AE Project Number: 689-22-700 WSP Project Number: US-WSP-31800188.7295

April 3, 2026

Prepared by Peter Bailey, P.E.

1 GENERAL DESCRIPTION

1.1 PURPOSE

The purpose of this report is to detail the drainage design and calculations that were performed for the new MCR (Main Computer Room) Building 41 and Generator Building 42 site development as part of the overall EHRM (Electronic Health Records Modernization) project at the West Haven, CT VA Campus. This document includes the following:

• Pre-development and post-development conditions

• Design storm event

• Onsite storm water management calculations

1.2 PROJECT SITE

The project site for the MCR and generator buildings is located in a courtyard near the center of the West Haven VA campus between buildings 3, 4, 21, 27, and 38. The site is bordered by buildings to the north, south, and east, with an asphalt parking lot between buildings 21 and 38 to the west and a pedestrian walkway between buildings 21 and 27 to the north. The existing ground coverage is mainly grassy lawns between existing concrete sidewalks running from building to building and other paved areas.

See vicinity map Exhibit 1 in Appendix A.

The West Haven VA campus is not located within a mapped floodplain. See FEMA Flood Insurance Rate Map in Appendix A.

The project site was determined to be located within the Type III rainfall distribution.

See the NRCS (SCS) Rainfall Distribution Map in Appendix A.

1.3 DESIGN CRITERIA

The following design criteria were utilized for the preparation of the drainage calculations and report:

• Connecticut Stormwater Quality Manual, September 30, 2023

• Site Design Manual, U.S. Department of Veterans Affairs, rev April 1, 2021

• Technical Guidance on Implementing the Stormwater Runoff Requirements for Federal Projects under Section 438 of the Energy Independence and Security Act, December 2009

• TR-55 Urban Hydrology for Small Watersheds, United States Department of Agriculture, June 1986

1.4 DESIGN METHODOLOGY

The EPA developed the technical guidance in EISA 438 to outline storm water runoff requirements for federal development or redevelopment projects. Any projects on a federal facility with a footprint that exceeds 5,000 square feet are subject to these requirements. The intent is to maintain or restore the pre-development site hydrology during the development or redevelopment process. Implementation of EISA 438 is commonly achieved using green infrastructure/low impact development (GI/LID) best management practices (BMPs). The stormwater management design and calculations for the new MCR building followed EISA 438.

The VA site design manual (PG 18-10) requires local stormwater management and permitting requirements to be researched. All applicable local requirements must be considered and the more stringent requirement between federal, state, and local regulations shall be used.

The onsite storm water management for this project was designed in accordance with the Connecticut Stormwater Quality Manual (stormwater manual).

2 PRE & POST-DEVELOPMENT

CONDITIONS

2.1 Pre-Development Condition

The pre-development condition of the site is mostly pervious surface consisting of grassy lawn with concrete sidewalks, a gravel drive connecting the asphalt parking to the west to a paved basketball court, and a covered concrete patio and walkway south of building 27. See pre-development Exhibit 2 in Appendix A.

According to NRCS Web Soil Survey, the site soils consist of Udorthents (gravelly and very gravelly sandy loam). It is classified as well drained and USDA NRCS Hydrologic Soil Group B; however differing conditions were found during explorations. See Web Soil Survey Map in Appendix A.

According to the geotechnical investigation prepared by GEOTILL Engineering, Inc. on April 17, 2024, the site soil generally consists of 12” of topsoil materials, followed by several feet of fill material, then hard sandy clay or clayey sand, and medium dense to very dense silty sand at greater depths. The performed infiltration test provided an infiltration rate of 0.22 inches/hour; infiltration is not feasible for this site. See geotechnical report in Appendix C.

2.2 Post-Development Condition

The post-development condition consists of all site improvements to the existing site that have taken place after construction completion. Site development for the new MCR building includes the following:

• Impervious surfaces: MCR building roof, generator building roof, mechanical yard, and concrete sidewalks.

• Pervious surfaces: Landscaping restoration areas adjacent to MCR and generator buildings and hardscape improvements.

See post-development Exhibit 3 in the Appendix A.

3 DESIGN STORM EVENT

3.1 Rainfall Data

The rainfall estimates for West Haven, Connecticut are based on the NOAA Atlas 14, Volume 10, Version 3 Precipitation Frequency Data Server. These rainfall values are listed in the stormwater manual in chapter 4, figure 4- 4.

Return Interval (year)

24-hour Rainfall Total (inches)

1 2.72

2 3.35

5 4.38

10 5.23

25 6.41

50 7.28

100 8.23

3.2 Time of Concentration

Due to the relatively small project footprint, the time of concentration (Tc) for both pre-developed and post-developed conditions was assumed to be the minimum value of 0.167 hours or 10 minutes (stormwater manual, Appendix D).

4 STORMWATER MANAGEMENT

CALCULATIONS

4.1 Low Impact Development (LID) BMP Selection

The requirements of EISA 438 to implement a LID BMP is not feasible for this site due to project footprint constraints and limited on-site soil infiltration capacity.

Within the project site, there is no feasible area to place a LID facility. There are too many existing and proposed utilities in and around the MCR and generator buildings.

As previously noted, the onsite soils have a very low infiltration capacity that makes infiltration BMPs infeasible for this site.

The COR provided direction to utilize a BMP used previously on other campus projects. Due to the presence of pollution generating impervious surfaces to be constructed for this project, a water quality treatment BMP (Best Management Practice) is required. The BMP selected for this project is a proprietary structural BMP (Cascade Separator designed by Contech Engineered Solutions).

This BMP is located just northwest of the proposed MCR Building and its sidewalk. The roof runoff from both the MCR building and generator building will be collected via roof drain lines, which will connect to the nearest storm structure. There are 6 yard drains on the south and west sides of the MCR building with graded low points that will collect runoff from the sidewalk and pervious areas, and an area drain to collect runoff inside the generator building mechanical yard. The runoff will flow through underground storm lines around the perimeter of the MCR building and through the pervious area between the MCR and generator buildings until it reaches the structural storm BMP for treatment, where it will then flow north to connect to an existing storm structure. Any runoff to the west of the generator building will sheet flow across proposed grades to the existing asphalt parking lot to the west, where it will be collected by existing storm drains. For higher runoff storm events, the BMP has an internal bypass structure that will release the excess runoff into the outlet pipe directly.

4.2 Stormwater Facility Design Calculations

The stormwater calculation process in the Connecticut Stormwater Quality Manual was followed to design the BMP according to the stormwater design standards (stormwater manual, chapter 4).

Standard #1 (Runoff Volume and Pollutant Reduction) was followed by calculating the Water Quality Volume (WQV) of runoff produced from the first 1.3 inches of a storm in order to collect and treat most of the post-developed stormwater pollutant load as well as help maintain pre-development stormwater conditions. The Water Quality Flow (WQF) was calculated using the modified curve number method. This flowrate was used to size the structural stormwater BMP. For this project, the Required Retention Volume (RRV) is 100% of the WQV due to the proposed work being redevelopment where the existing directly contributing impervious area is less than 40%. Due to the low soil infiltration rate and space constraints on the site, an onsite stormwater management BMP is not feasible for this project. Furthermore, since the full RRV is being treated, it is assumed per the stormwater manual that pollutant reduction is also achieved and no additional pollutant calculations are necessary.

Standard #2 (Stormwater Runoff Quantity Control) was followed by calculating the peak flow rates (qp) of the 2, 10, and 100-year, 24-hour storm events and ensuring the stormwater system and structural BMP can convey the peak flow rates. The peak flow depths for post-development conditions were calculated with the SCS Curve Number Method (stormwater manual, chapter 4), then used to calculate the peak discharge flow rates with the TR-55, Graphical Peak Discharge Method (TR-55, chapter 4). These flow rates were calculated for the 2, 10, and 100-year storms respectively.

Using Manning’s Equation, the maximum capacity of the proposed storm was calculated to ensure the outlet pipe has the capacity to pass the 100-year storm. The structural storm BMP internal bypass also has adequate capacity to pass the 100-year storm.

See spreadsheet calculations of the stormwater design in Appendix B.

APPENDIX A - EXHIBITS

WSP USA Inc.

1201 Pacific Avenue Suite 550 Tacoma, WA 98402

TEL: (206) 431-2300

FAX: (206) 431-2250

U.S. Department of Veterans Affairs

VA WEST HAVEN EHRM PROJECT

NEW MCR BUILDING ADDITION

EXHIBIT 1

VICINITY MAP

PROJECT

LOCATION

NOT TO SCALE

SDSD

W

W

W

W

W W

W

W

E

E

E

E E

E

E

E

E E

E

E W

W

W

E

F

V

CO

ER

ER

ER

W

W

CO

M

M E

W

E E W

SAN

SAN

SDSD

W

E

E

W

WE

ER

SD

SD

SDSD

SAN

SAN

SAN

X

D

E

WG

E

WG

Y

WG

E

Y

AC

Y

S

Y

Y

AC

AC

Y

CO

Y

AC

Y

S

P

Y

E

SDSD

COMM

E

SD

SD

SD

SD

BLDG 3

BLDG 4

BLDG 27

FFE = 107.54

BLDG 38

BLDG 21

PRE-DEVELOPED AREA

AREA TYPE AREA (ACRE)

BUILDING 0

PAVEMENT 0.11

PERVIOUS 0.23

TOTAL 0.34

PRE-DEVELOPED CONDITIONS EXHIBIT

U.S. Department of Veterans Affairs

VA WEST HAVEN EHRM PROJECT

NEW MCR BUILDING ADDITION

EXHIBIT 2

PRE-DEVELOPED CONDITIONS

SCALE: 1" = 30'

PROJECT

LIMITS

EXISTING

DRAINAGE INLET

WSP USA Inc.

1201 Pacific Avenue Suite 550 Tacoma, WA 98402

TEL: (206) 431-2300

FAX: (206) 431-2250

SDSD

W

W

W

W

W W

W

W

E

E

E

E E

E

E

E

E E

E

E W

E

F

V

CO

ER

ER

ER

CO

M

M E

E E W

SAN

SAN

SDSD

W

E

E

W

WE

ER

SAN

SAN

SAN

X

D

E

WG

E

WG

Y

WG

E

Y

AC

Y

S

Y

AC

AC

AC

S

P

E

SDSD

COMM

E

SD

SD

SD

SD

BLDG 3

BLDG 4

BLDG 27

FFE = 107.54

BLDG 38

BLDG 21

E

E

E

E

E

E

E

E

W

SD

E

C(B)

C(B)

C(B)

SD

BLDG 41

BLDG 42

C(B)

W

F

F

W

E

E

E

E

E

E

C(B)

C(B)

C(B)

C(B)

C(B)

C(B)

C(B)

C(B)

C(B)

C(B)

F C

H W

S

CHW

S

CHW

S

SD

SSFM

SSFM

SSFM

SSFM

SSFM

SSFM

W

W

F

U.S. Department of Veterans Affairs

POST-DEVELOPED AREA

AREA TYPE AREA (ACRE)

BUILDING 0.11

PAVEMENT 0.05

PERVIOUS 0.18

TOTAL 0.34

POST-DEVELOPED CONDITIONS EXHIBIT

VA WEST HAVEN EHRM PROJECT

NEW MCR BUILDING ADDITION

EXHIBIT 3

POST-DEVELOPED CONDITIONS

SCALE: 1" = 30'

WSP USA Inc.

1201 Pacific Avenue Suite 550 Tacoma, WA 98402

TEL: (206) 431-2300

FAX: (206) 431-2250

National Flood Hazard Layer FIRMette

0 500 1,000 1,500 2,000250 Feet

Ü

SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT

SPECIAL FLOOD

HAZARD AREAS

Without Base Flood Elevation (BFE) Zone A, V, A99

With BFE or DepthZone AE, AO, AH, VE, AR

Regulatory Floodway

0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mileZone X

Future Conditions 1% Annual Chance Flood HazardZone X

Area with Reduced Flood Risk due to Levee. See Notes.Zone X

Area with Flood Risk due to LeveeZone D

NO SCREENArea of Minimal Flood HazardZone X

Area of Undetermined Flood HazardZone D

Channel, Culvert, or Storm Sewer

Levee, Dike, or Floodwall

Cross Sections with 1% Annual Chance

17.5 Water Surface Elevation

Coastal Transect

Coastal Transect Baseline Profile Baseline Hydrographic Feature

Base Flood Elevation Line (BFE)

Effective LOMRs

Limit of Study Jurisdiction Boundary

Digital Data Available

No Digital Data Available

Unmapped

This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below.

The basemap shown complies with FEMA's basemap accuracy standards

The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 12/26/2023 at 12:30 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time.

This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes.

Legend

OTHER AREAS OF

FLOOD HAZARD

OTHER AREAS

GENERAL

STRUCTURES

OTHER

FEATURES

MAP PANELS

B 20.2

The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location.

1:6,000

72°57'57"W 41°17'19"N

72°57'20"W 41°16'52"N

Basemap Imagery Source: USGS National Map 2023

B–2 (210-VI-TR-55, Second Ed., June 1986)

1203312033

2500125001

2608326083

CTCT

DEDE

FLFL

Type I

Type IA

Type II

Type III

III

III

III

I

IA

I I

III

Rainfall

Distribution

Figure B-2 Approximate geographic boundaries for NRCS (SCS) rainfall distributions

Rainfall data sources This section lists the most current 24-hour rainfall data published by the National Weather Service (NWS) for various parts of the country. Because NWS Technical Paper 40 (TP-40) is out of print, the 24-hour rainfall maps for areas east of the 105th meridian are included here as figures B-3 through B-8. For the area generally west of the 105th meridian, TP-40 has been superseded by NOAA Atlas 2, the Precipitation-Frequency Atlas of the Western United States, published by the National Ocean and Atmospheric Administration.

East of 105th meridian

Hershfield, D.M. 1961. Rainfall frequency atlas of the United States for durations from 30 minutes to 24 hours and return periods from 1 to 100 years. U.S.

Dept. Commerce, Weather Bur. Tech. Pap. No. 40.

Washington, DC. 155 p.

West of 105th meridian

Miller, J.F., R.H. Frederick, and R.J. Tracey. 1973.

Precipitation-frequency atlas of the Western United States. Vol. I Montana; Vol. II, Wyoming; Vol III, Colo-rado; Vol. IV, New Mexico; Vol V, Idaho; Vol. VI, Utah;

Vol. VII, Nevada; Vol. VIII, Arizona; Vol. IX, Washing-ton; Vol. X, Oregon; Vol. XI, California. U.S. Dept. of

Commerce, National Weather Service, NOAA Atlas 2.

Silver Spring, MD.

Alaska

Miller, John F. 1963. Probable maximum precipitation and rainfall-frequency data for Alaska for areas to 400 square miles, durations to 24 hours and return periods from 1 to 100 years. U.S. Dept. of Commerce, Weather Bur. Tech. Pap. No. 47. Washington, DC. 69 p.

Hawaii

Weather Bureau. 1962. Rainfall-frequency atlas of the Hawaiian Islands for areas to 200 square miles, dura-tions to 24 hours and return periods from 1 to 100 years. U.S. Dept. Commerce, Weather Bur. Tech. Pap.

No. 43. Washington, DC. 60 p.

Puerto Rico and Virgin Islands

Weather Bureau. 1961. Generalized estimates of prob-able maximum precipitation and rainfall-frequency data for Puerto Rico and Virgin Islands for areas to 400 square miles, durations to 24 hours, and return periods from 1 to 100 years. U.S. Dept. Commerce, Weather Bur. Tech. Pap. No. 42. Washington, DC. 94 P.

Project Location

Soil Map—State of Connecticut, Western Part (West Haven VA Campus)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

3/19/2024

670100 670200 670300 670400 670500 670600 670700 670800 670900 671000 671100 671200 671300 671400 671500 671600

670100 670200 670300 670400 670500 670600 670700 670800 670900 671000 671100 671200 671300 671400 671500 671600

41° 17' 15'' N

8'

'' W 41° 17' 15'' N

7'

'' W

41° 16' 47'' N

8'

'' W

41° 16' 47'' N

7'

'' W

N

Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 200 400 800 1200

Feet 0 50 100 200 300

Meters Map Scale: 1:4,170 if printed on B landscape (17" x 11") sheet.

Soil Map may not be valid at this scale.

MCR Bldg Site

MAP LEGEND MAP INFORMATION

Area of Interest (AOI) Area of Interest (AOI)

Soils Soil Map Unit Polygons

Soil Map Unit Lines

Soil Map Unit Points

Special Point Features Blowout

Borrow Pit

Clay Spot

Closed Depression

Gravel Pit

Gravelly Spot

Landfill

Lava Flow

Marsh or swamp

Mine or Quarry

Miscellaneous Water

Perennial Water

Rock Outcrop

Saline Spot

Sandy Spot

Severely Eroded Spot

Sinkhole

Slide or Slip

Sodic Spot

Spoil Area

Stony Spot

Very Stony Spot

Wet Spot

Other

Special Line Features

Water Features Streams and Canals

Transportation Rails

Interstate Highways

US Routes

Major Roads

Local Roads

Background Aerial Photography

The soil surveys that comprise your AOI were mapped at 1:12,000.

Warning: Soil Map may not be valid at this scale.

Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale.

Please rely on the bar scale on each map sheet for map measurements.

Source of Map: Natural Resources Conservation Service Web Soil Survey URL:

Coordinate System: Web Mercator (EPSG:3857)

Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required.

This product is generated from the USDA-NRCS certified data as of the version date(s) listed below.

Soil Survey Area: State of Connecticut, Western Part Survey Area Data: Version 1, Sep 15, 2023

Soil map units are labeled (as space allows) for map scales 1:50,000 or larger.

Date(s) aerial images were photographed: Jun 14, 2022—Oct 6, The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident.

Soil Map—State of Connecticut, Western Part (West Haven VA Campus)

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

3/19/2024

Map Unit Legend

Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI

13 Walpole sandy loam, 0 to 3 percent slopes

0.4 0.2%

77C Cheshire-Holyoke complex, 3 to 15 percent slopes, very rocky

0.6 0.3%

77D Cheshire-Holyoke complex, 15 to 35 percent slopes, very rocky

8.7 4.7%

235B Penwood-Urban land complex, 0 to 8 percent slopes

39.6 21.4%

263C Cheshire-Urban land complex, 8 to 15 percent slopes

49.3 26.7%

306 Udorthents-Urban land complex

67.8 36.6%

308 Udorthents, smoothed 18.6 10.1%

Totals for Area of Interest 185.0 100.0%

Soil Map—State of Connecticut, Western Part West Haven VA Campus

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

State of Connecticut, Western Part

306—Udorthents-Urban land complex

Map Unit Setting National map unit symbol: 9lmg Elevation: 0 to 2,000 feet Mean annual precipitation: 43 to 56 inches Mean annual air temperature: 45 to 55 degrees F Frost-free period: 120 to 185 days Farmland classification: Not prime farmland

Map Unit Composition Udorthents and similar soils: 50 percent Urban land: 39 percent Minor components: 11 percent Estimates are based on observations, descriptions, and transects of the mapunit.

Description of Udorthents

Setting Parent material: Human-transported material

Typical profile ^A - 0 to 5 inches: loam ^C1 - 5 to 21 inches: gravelly loam ^C2 - 21 to 79 inches: very gravelly sandy loam

Properties and qualities Slope: 0 to 25 percent Depth to restrictive feature: More than 80 inches Drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Very low to high (0.00 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water supply, 0 to 60 inches: Moderate (about 6.8 inches)

Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4e Hydrologic Soil Group: B Hydric soil rating: No

Description of Urban Land

Typical profile M - 0 to 6 inches: cemented material

Map Unit Description: Udorthents-Urban land complex---State of Connecticut, Western Part West Haven VA Campus

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 8 Hydrologic Soil Group: D Hydric soil rating: Unranked

Minor Components

Udorthents, wet substratum Percent of map unit: 9 percent Hydric soil rating: No

Rock outcrop Percent of map unit: 2 percent Landform: Hills Down-slope shape: Convex Across-slope shape: Convex Hydric soil rating: No

Data Source Information

Soil Survey Area: State of Connecticut, Western Part Survey Area Data: Version 1, Sep 15, 2023

Map Unit Description: Udorthents-Urban land complex---State of Connecticut, Western Part West Haven VA Campus

Natural Resources Conservation Service

Web Soil Survey National Cooperative Soil Survey

APPENDIX B - CALCULATIONS

Pre-Developed Tributary Area

Ground Cover sf acre mi

Building 0 0.00 0.00000

Pavement 4928 0.11 0.00018

Pervious 9844 0.23 0.00035

Total 14772 0.34 0.00053

Post-Developed Tributary Area

Ground Cover sf acre mi

Building 4968 0.11 0.00018

Pavement 2127 0.05 0.00008

Pervious 7677 0.18 0.00028

Total 14772 0.34 0.00053

Standard 1 - Runoff Volume and Pollutant Reduction (ch 4, pg 38)

Pre-Developed: Post-Developed:

WQV (cf) 561 WQV (cf) 772 pg 46

P (in) 1.30 P (in) 1.30 given

R 0.35 R 0.48

I 33 I 48

A (sf) 14772 A (sf) 14772

WQF (cfs) 0.13 WQF (cfs) 0.19 pg 523

CN 88.33 CN 91.85 pg 520

P (in) 1.3 P (in) 1.3 pg 521, given, 100% WQV

Q (in) 0.46 Q (in) 0.63 pg 521 tc (hr) 0.167 tc (hr) 0.167 pg 522, assumed minimum

Ia 0.273 Ia 0.222 pg 522, Figure 2

Ia/P 0.210 Ia/P 0.171

C0 2.431 C0 2.446

C1 -0.515 C1 -0.516

C2 -0.150 C2 -0.157 log(qu) 2.741 log(qu) 2.752 qu (csm/in) 550.70 qu (csm/in) 565.49

Standard 2 - Stormwater Runoff Quantity Control (ch 4, pg 52)

Duration (hrs) 1-year 2-year 5-year 10-year 25-year 50-year 100-year

24 2.72 3.35 4.38 5.23 6.41 7.28 8.23 inches

Pre-Developed Conditions (TR-55, table 2-2a, equation 2-2 and 2-4):

Cover Type Soil Type Area (sf) Area (ac) CN S Ia

Pavement B 4928 0.11 98 NA NA

Building B 0 0.00 98 NA NA

Open space

(fair)

B 9844 0.23 69 NA NA

Total 14772 0.34 78.68 2.71 0.54

Storm Event P (in) Q (in) Ia/P C0 C1 C2 log(qu) qu

(csm/in) qp

(cfs)

2-year 3.35 1.43 0.16 2.449 -0.516 -0.159 2.755 568.916 0.43

10-year 5.23 2.97 0.10 2.472 -0.518 -0.170 2.772 591.717 0.93

100-year 8.23 5.68 0.07 2.486 -0.520 -0.177 2.783 607.014 1.83

Post-Developed Conditions (TR-55, table 2-2a, equation 2-2 and 2-4):

Cover Type Soil Type Area (sf) Area (ac) CN S Ia

Pavement B 2127 0.05 98 NA NA

Building B 4968 0.11 98 NA NA

Open space

(fair)

B 7677 0.18 69 NA NA

Total 14772 0.34 82.93 2.06 0.41

Storm Event P (in) Q (in) Ia/P C0 C1 C2 log(qu) qu

(csm/in) qp

(cfs)

2-year 3.35 1.73 0.12 2.464 -0.518 -0.166 2.766 584.074 0.53

10-year 5.23 3.38 0.08 2.481 -0.519 -0.175 2.779 601.767 1.08

100-year 8.23 6.19 0.05 2.492 -0.520 -0.180 2.788 613.546 2.01

Storm Pipe Capacity (Manning's Equation)

Size (in) 10

Depth (ft) 0.833

Radius (ft) 0.417

Flow Angle 360.0

Area (sf) 0.545

Slope (ft/ft) 0.0100 n 0.010

R 2/3

0.351

Q (cfs) 2.86

Velocity (fps) 5.24

Storm BMP pipes

APPENDIX C – GEOTECH REPORT

Nationwide Coverage

GEOTECHNICAL ENGINEERING INVESTIGATION

Proposed EHRM Infrastructure Upgrade

950 Campbell Ave

West Haven, CT

GEOTILL Project No. 112452001

Prepared For:

Spees Design Build

Attn: Mr. Dominic Ditschler

Cad Technician

April 17, 2024

7732 Loma Court

Fishers, IN 46038

Ph. 317-449-0033 Fax 317- 285-0609 (info@geotill.com)

Geotechnical, Environmental and Construction Materials Testing Professionals

GEOTILL Inc.

Geotechnical Engineering• Subsurface Exploration • Construction Testing and Material Engineering

7732 Loma Court Fishers, Indiana 46038

Phone 317.449.0033 Fax 317.285.0609 www.geotill.com

Geotechnical Engineering• Subsurface Exploration • Construction Testing and Material Engineering

Nationwide Coverage

Spees Design Build

Attention: Mr. Dominic Ditschler

Cad Technician

Re: Geotechnical Engineering Investigation

950 Campbell Ave

Gentlemen:

Submitted herewith is the report of our geotechnical engineering investigation for the referenced project. This study was authorized in accordance with GEOTILL Proposal PE- 03021124 dated

March 3, 2024.

This report contains the results of our field and laboratory-testing program, an engineering interpretation of this data with respect to the available project characteristics and recommendations to aid design and construction of foundations and other earth-connected phases of this project. We wish to remind you that we will store the samples for 30 days after which time they will be discarded unless you request otherwise.

We appreciate the opportunity to be of service to you on this project. If we can be of any further assistance, or if you have any questions regarding this report, please do not hesitate to contact either of the undersigned.

Sincerely, GEOTILL INC.

Fawzy Ezzein Malek Smadi

Fawzy Ezzein, Ph.D. Malek Smadi, Ph.D., P.E.

Project Engineer Principal Engineer

(317) 449-0033 Ext. 101

Copies: Spees Design Build, Attn: Mr. Dominic Ditschler file:///C:/SkyDrive/Proposals/1213-0803%20Pizza%20Hut%20Building,%20Fishers%20%20ok/www.geotill.com

TABLE OF CONTENTS

Page

1.0 PURPOSE AND SCOPE ----------------------------------------------------------------------------------------------------- 1

2.0 PROJECT CHARACTERISTICS ------------------------------------------------------------------------------------------- 1

3.0 GENERAL SUBSURFACE CONDITIONS ------------------------------------------------------------------------------ 2

3.1 Subsurface Soil Conditions ---------------------------------------------------------------------------------------------- 2

3.2 Groundwater --------------------------------------------------------------------------------------------------------------- 3

3.3 Geology -------------------------------------------------------------------------------------------------------------------- 3

3.4 Site Seismic Class -------------------------------------------------------------------------------------------------------- 4

3.5 Infiltration ----------------------------------------------------------------------------------------------------------------- 5

4.0 SUMMARY OF FINDINGS AND RECOMMENDATIONS ---------------------------------------------------------- 6

4.1 Footings -------------------------------------------------------------------------------------------------------------------- 6

4.2 Floor Slabs ----------------------------------------------------------------------------------------------------------------- 8

4.3 Site Grading --------------------------------------------------------------------------------------------------------------- 8

5.0 GENERAL CONSTRUCTION PROCEDURES AND RECOMMENDATIONS ----------------------------------- 9

5.1 Site Preparation ----------------------------------------------------------------------------------------------------------- 9

5.2 Fill Compaction --------------------------------------------------------------------------------------------------------- 10

5.3 Foundation Excavations------------------------------------------------------------------------------------------------ 10

5.4 Construction Dewatering ---------------------------------------------------------------------------------------------- 11

5.5 Construction Monitoring ----------------------------------------------------------------------------------------------- 11

6.0 FIELD INVESTIGATION ------------------------------------------------------------------------------------------------- 12

7.0 LABORATORY INVESTIGATION ------------------------------------------------------------------------------------- 12

8.0 LIMITATIONS OF STUDY ----------------------------------------------------------------------------------------------- 13

APPENDIX ------------------------------------------------------------------------------------------------------------------------ 14

GEOTECHNICAL ENGINEERING INVESTIGATION

Proposed EHRM Infrastructure Upgrade

950 Campbell Ave

1.0 PURPOSE AND SCOPE

The purpose of this study was to determine the general subsurface conditions at the project site by drilling two soil test borings and performing one infiltration test and to evaluate this data with respect to foundation concept and design for the Proposed EHRM Infrastructure

Upgrade construction and pavement field design. Also included is an evaluation of the site with respect to potential construction problems and recommendations dealing with earthwork and quality control during construction.

2.0 PROJECT CHARACTERISTICS

Spees Design Build is planning the construction of a new MCR Building and EHRM

Infrastructure Upgrade on a site located at 950 Campbell Ave, West Haven, CT. The location of the proposed construction site is shown on Figure 1 in the Appendix. The ground surface at the site is characterized as relatively flat and is currently grass covered.

The proposed construction will consist of New MCR Building and EHRM Infrastructure

Upgrade. The general layout of the project is shown on Figure 2 in the Appendix. It is our understanding that the proposed finish floor elevation for the building is planned to be slightly above the existing grade. Therefore, it is assumed that up to about 2 ft. of fill will be required in some locations to establish the finish grade elevation for the building.

Geotechnical Engineering Investigation

Details regarding structural loads are not available at this time. No unusual loading conditions or settlement restrictions have been specified.

3.0 GENERAL SUBSURFACE CONDITIONS

3.1 Subsurface Soil Conditions

The general subsurface conditions were investigated by drilling two (2) soil test borings

(B-1 and B-2) to a depth of twenty (20) ft within the area of the proposed building and performing 1 infiltration test (P-1) to a depth of 5 ft as shown in the Boring Plan (Figure

2 in the Appendix). (B-1 and B-2) were offset 5 ft, and 9 ft respectively due to the existence of underground utilities. The subsurface conditions disclosed by the field investigation are summarized in the following paragraphs. Detailed descriptions of the subsurface conditions encountered in each test boring are presented on the test boring logs in the Appendix. The letters in parentheses following the soil descriptions are the soil classifications in general accordance with the Unified Soil Classification System. It should be noted that the stratification lines shown on the soil boring logs represent approximate transitions between material types. In-situ stratum changes could occur gradually or at slightly different depths.

All of the soil test borings revealed approximately 12.0 inches of topsoil on the surface. Soil test boring B-1 had very loose to dense and hard Fill Material from depths of 1.0 to 10.0 ft followed by hard sandy Clay (CL) from depths of 10.0 to 13.0 ft, and ended with medium dense to dense clayey silty Sand (SM) from depths of 13.0 ft to termination at 20.0 ft. Soil test boring B-2 had very loose to dense clayey Sand (SC) from depths of 1.0 to 6.0 ft and ended with medium dense to very dense silty Sand (SM) from depths of 6.0 ft to auger refusal at 18.0 ft. Both borings had layers of very loose soils which is an area of concern.

The consistency of the cohesive soils and the density of the cohesionless soils were estimated based upon the results of the standard penetration test (ASTM D-1586).

Zones of very loose soil encountered at the site are summarized in the table shown below:

Very Loose Soils

Boring No. Soil Type Depth, ft Consistency/

Density

B-1 Fill Material 1.0 – 4.0 Very Loose

B-2 clayey Sand (SC) 1.0 – 4.0 Very Loose

3.2 Groundwater

Ground water observations are made during the drilling operations by noting the depth of water on the drilling tools and in the open boreholes following withdrawal of the drilling augers. No free ground water was noted in test borings upon completion and on tooling during drilling activities. It should be noted that short-term ground water readings in the test borings are not usually a reliable indication of the actual ground water level and that fluctuations in the level of the ground water should be expected due to variations in rainfall and other factors.

3.3 Geology

West Haven is a city in New Haven County, Connecticut, it lies within the state's diverse geological regions: eastern and western highlands made of older, metamorphic rock, and a central valley primarily consisting of basalt covered by sandstone. Connecticut boasts a variety of rock types, including granite, basalt, sandstone, limestone, marble, schist, and slate. Pegmatite, an economically important rock, is prevalent in the state, with notable occurrences in Branchville and Middletown. The geological foundation of Connecticut developed from west to east, with the oldest rock formations, part of the Precambrian

Grenville Massif, dating back 1.3 billion years in Kent and the state, forming the eastern edge of the Laurentia continental plate.

3.4 Site Seismic Class

Based on geologic mapping, the results of the test borings, it is our opinion that the subsurface conditions at this site meet the criteria for Site Class C based on Section 1613.3.2 of the International Building Code (Chapter 20 of ASCE 7-16 “Minimum Design Loads for

Buildings and Other Structures”). The basic seismic parameters are summarized in the following table:

3.5 Infiltration

One (1) infiltration test was performed to establish the infiltration rate. The location is shown in Figure 3 of the appendix. We understand that the results of the testing will be used to prepare a preliminary design for the proposed stormwater BMP that will be used at the project site. We drilled a soil boring and installed casing (solid four-inch ID) to the proposed depth at 5 ft. The casing was inserted within the augers before the augers were extracted. We removed any smeared soiled surfaces and provided a natural soil interface into which water may percolate. We removed all loose material from the casing, a two-inch layer of clean sand backfill was placed to protect the bottom from scouring and sediment. We Backfilled the annulus around the bottom of the casing with at least 24 inches around the casing with hydrated granular bentonite.

Casing was filled with potable water to the top of casing and allowed to pre-soak for 24 hours, once pre-soak period has completed, we filled the top of the casing with potable water and monitor water level (measured drop from the top of the casing) until termination and stabilization criteria has been established based on the state and local stormwater requirements. Measurements were made using an electric water level probe indicator. We

Repeated this procedure (filling the casing each time) a minimum of three additional times.

Upon completion of the testing, the casing was immediately pulled, and the boring backfilled. The final field rate is reported in inches per hour as shown below.

Table 1: Infiltration Test Results

Boring # Depth

(ft) Percolation Rate (in/hr)

Infiltration Rate*

(in/hr)

P-1 5 8.27 in/hr 0.22

4.0 SUMMARY OF FINDINGS AND RECOMMENDATIONS

The following findings and recommendations have been developed on the basis of the previously described project characteristics (Section 2.0) and subsurface conditions (Section

3.0). If there is any change in these project criteria, including project location on the site, a review should be made by this office.

4.1 Footings

Our findings show that the proposed building can be supported on shallow spread footings provided that any unsuitable materials or any uncontrolled fill material or any soft soils are identified and removed at the proposed footing locations. It is recommended to undercut and replace the upper 4 feet with engineered fill in the area of footings.

Footings that bear on firm natural soil (or on well-compacted engineered fill that is placed over firm natural soil) can be designed for a net allowable soil pressure of 2,500 lbs/sq.ft for both column (square type) and wall (strip type) footings. It is important that the soil at the base of each footing excavation be carefully inspected as described in

Section 5.3 to ensure that pockets of soft natural soils and any uncontrolled fill materials are identified and removed from beneath the footings and that the footings will bear on suitable materials.

In using net pressure, the weight of the footing and backfill over the footing, including the weight of the floor slab, need not be considered; hence, only loads applied at or above the finished floor need to be used for dimensioning the footings. Wall footings should be at least 2 ft. wide and column footings should be at least 3 ft. wide for bearing capacity considerations.

All exterior footings and footings in unheated areas should be located at a depth of at least 4 ft. below the final exterior grade for frost protection. Interior footings can be located at nominal depths below the finished floor provided the topsoil and other undesirable materials are removed at the footing locations.

Provided that the footings are designed as prescribed herein and inspected as outlined in

Section 5.3, it is estimated that the total and differential foundation settlements should not exceed about 1 in. and 1/2 in., respectively. Careful field control will contribute substantially to minimizing the settlements.

Lateral forces on a shallow spread footing can be resisted by the passive lateral earth pressure against the side of the footing and by friction between the subgrade soil and the base of the footing. An allowable passive pressure of 500 lbs./sq.ft can be used for that portion of the footing that is below a depth of 2.5 ft. below the final exterior grade (no portion of the footing above this depth should be used for lateral resistance). An allowable coefficient of friction (between the base of the footing and the underlying soil) of 0.3 can be used in conjunction with the minimum downward load on the base of the footing.

Uplift forces on the footings can be resisted by the weight of the footings and the soil material that is placed over the footings. It is recommended that the soil weight be limited to that immediately above and within the perimeter of the footings (unless a much higher factor of safety is used). A total soil unit weight of 110 lbs./cu. ft. can be used for the backfill material above the footings, provided it is compacted as recommended in

Section 5.2. It is also recommended that a factor of safety of at least 1.3 be used for calculating uplift resistance from the footings (provided only the weight of the footing, and the soil immediately above it, is used to resist uplift forces).

4.2 Floor Slabs

Floor slabs can be supported on firm existing soils or on compacted structural fill. The slab subgrade should be prepared and inspected as described in Section 5.1 of this report.

It is recommended that all floor slabs be "floating," that is, fully ground supported and not structurally connected to walls or foundations. This is to minimize the possibility of cracking and displacement of the floor slabs because of differential movements between the slab and the foundation. Although the movements are estimated to be within the tolerable limits for structural safety, such movements could be detrimental to the slabs if they were rigidly connected to the foundations.

It is furthermore recommended that the floor slab be supported on a 6-in. layer of relatively clean granular material such as sand and gravel or crushed stone. This is to help distribute concentrated loads and equalize moisture conditions beneath the slab. Provided that a minimum of 6 in. of granular material is placed below the slab, a modulus of subgrade reaction (k30) of 125 lbs./cu.in. can be used for design of the floor slabs.

4.3 Site Grading

Adequate drainage should be provided at the site to minimize any increase in moisture content of the foundation soils. The exterior grade should be sloped away from the structure to prevent ponding of water.

5.0 GENERAL CONSTRUCTION PROCEDURES

AND RECOMMENDATIONS

Since this investigation identified actual subsurface conditions only at the test boring locations, it was necessary for our geotechnical engineers to extrapolate these conditions in order to characterize the entire project site. Even under the best of circumstances, the conditions encountered during construction can be expected to vary somewhat from the test boring results and may, in the extreme case, differ to the extent that modifications to the foundation recommendations become necessary. Therefore, we recommend that GEOTILL be retained as the geotechnical consultant through the earth-related phases of this project to correlate actual soil conditions with test boring data, identify variations, conduct additional tests that may be needed, and recommend solutions to earth-related problems that may develop.

5.1 Site Preparation

All areas that will support floor slabs and pavements should be properly prepared. After rough grade has been established in cut areas and prior to placement of fill in all fill areas, the exposed subgrade should be carefully inspected by the geotechnical engineer or a qualified soils technician by probing and testing as needed. Any topsoil or other organic material still in place, frozen, wet, soft soil and other undesirable materials or soft fill material should be removed. All loose sandy soils should be compacted. The exposed subgrade should furthermore be inspected by proof-rolling with suitable equipment to check for pockets of soft material hidden beneath a thin crust of better soil. Any unsuitable materials thus exposed should be removed and replaced with well-compacted, engineered fill as outlined in Section 5.2.

Care should be exercised during the grading operations at the site. Due to the nature of the near surface soils, the traffic of construction equipment may create pumping and general deterioration of the shallower soils, especially if excess surface water is present. The grading, therefore, should be done during a dry season, if at all possible.

5.2 Fill Compaction

All engineered fill beneath floor slabs, footings and pavements should be compacted to a dry density of at least 98 percent of the standard Proctor maximum dry density (ASTM D-698).

The compaction should be accomplished by placing the fill in about 8 in. (or less) loose lifts and mechanically compacting each lift to at least the specified minimum dry density. Field density tests should be performed on each lift as necessary to ensure that adequate moisture conditioning and compaction is being achieved.

Compaction of any fill by flooding is not considered acceptable. This method will generally not achieve the desired compaction and the large quantities of water will tend to soften the foundation soils.

All-natural soils encountered in the test borings made at this site are considered suitable as general fill material. The need for some aeration or modification of any clayey soils should be expected before they can be placed and compacted to the specified density.

5.3 Foundation Excavations

The soil at the base of each footing excavation should be inspected by a geotechnical engineer or a qualified soils technician to ensure that all loose, soft or otherwise undesirable material is removed at footing locations and that the footing will bear on satisfactory material. At the time of such inspection, it will be necessary to make hand auger borings or use a hand penetration device in the base of the footing excavation to ensure that the soils below the base are satisfactory for support of the footing. The soils should be probed to a minimum depth of 3 ft. below the bottom-of-footing elevation.

Where undercutting is required to remove unsuitable materials and it is inconvenient to lower the footing, the proposed footing elevation may be re-established by backfilling after all undesirable materials have been removed. The undercut excavation beneath each footing should extend to suitable bearing soils. The dimensions of the excavation base should be determined by imaginary planes extending outward and downward on a 2

(vertical) to 1 (horizontal) slope from the base perimeter of the footing (see Figure 4 in the Appendix). The entire excavation should then be refilled with engineered fill. The engineered fill should be limited to well-graded sand and gravel or crushed stone compacted to the minimum dry density recommended in Section 5.2; or flowable fill or lean concrete may be used. Special care should be exercised to remove any sloughed, loose, or soft materials near the base of the excavation slopes. In addition, special care should be taken to "tie-in" the compacted fill with the excavation slopes with benches as necessary. This is to ensure that no pockets of loose or soft materials will be left in place along the excavation slopes below the foundation bearing level.

Soils exposed in the bases of all satisfactory foundation excavations should be protected against any detrimental change in condition such as from disturbance, rain and freezing.

Surface run-off water should be drained away from the excavation and not allowed to pond. If possible, all footing concrete should be placed the same day the excavation is made. If this is not practical, the footing excavations should be adequately protected.

5.4 Construction Dewatering

Based upon the ground water data obtained during drilling operations, it appears that dewatering is not required for the excavations during construction. In cases where cohesive soils are encountered in the base of excavations, it is expected that such dewatering can probably be handled by conventional dewatering methods such as pumping from sumps.

However, more extensive dewatering will be required where silty or sandy soils are encountered in the base of the excavation. The best dewatering system for each case must be determined at the time of construction based upon actual field conditions.

5.5 Construction Monitoring

We recommend that geotechnical engineer or designee be retained to continuously evaluate and test the subgrade and footing excavations before forming and placing steel or concrete.

If the soils upon which the footings are to be constructed become soft or disturbed, or if unsuitable materials are encountered, these materials should be removed and replaced with acceptable structural fill or as directed by the engineer.

Concrete strength and consistency tests should also be carried out, in accordance with the project specifications.

6.0 FIELD INVESTIGATION

Two soil test borings were drilled at the locations shown on the Boring Plan (Figure 2 in the

Appendix), and 1 infiltration test was performed to a depth of 5 ft. The borings were extended to depths of 20 ft. below the existing site grade. Split-spoon samples were obtained by the standard penetration test procedures (ASTM D-1586) at 2.5 ft intervals to a depth of 10 ft below the existing ground and at 5.0 ft intervals elsewhere.

Logs of the borings showing visual descriptions of all soil strata encountered using the

Unified Soil Classification System are included in the Appendix. Ground water observations, sampling information, and other pertinent field data and observations are also included. In addition, a sheet defining the terms and symbols used on the log and explaining the standard penetration test procedure is provided immediately following the boring log.

7.0 LABORATORY INVESTIGATION

The disturbed samples were inspected and classified in accordance with the Unified Soil

Classification System and the boring log was edited as necessary. To aid in classifying the soils and to determine general soil characteristics and natural moisture tests were performed on selected samples. The results of these tests are included on the boring logs.

8.0 LIMITATIONS OF STUDY

An inherent limitation of any geotechnical engineering study is that conclusions must be drawn on the basis of data collected at a limited number of discrete locations. The recommendations provided in this report were developed from the information obtained from the test boring which depicts the subsurface conditions only at the specific boring location and at the particular time designated on the log. Soil conditions at other locations may differ from conditions occurring at this boring location. The nature and extent of variations may not become evident until the course of construction. If variations then appear evident, it will be necessary to re-evaluate the recommendations of this report after performing on-site observations during the excavation period and noting the characteristics of any variation.

Our professional services have been performed, our findings obtained and our recommendations prepared in accordance with generally accepted geotechnical engineering principles and practices. This warranty is in lieu of all other warranties either expressed or implied. This company is not responsible for the independent conclusions, opinions, or recommendations made by others based on the field exploration and laboratory test data presented in this report. The scope of our geotechnical engineering services does not include any environmental assessment or investigation for the presence or absence of hazardous or toxic materials in the soil, ground water, or surface water within or beyond the site studied.

APPENDIX

Figure 1 - Vicinity Map (a-b)

Figure 2 - Boring Plan (a-d)

Figure 3 - Design Illustration - Footings in

Undercut Areas

Test Boring Logs

"Field Classification System for Soil Exploration"

FIGURE NO.