STORM WATER MODELING WEDGE QUARRY PASSIVE DRAINAGE SYSTEM

BENNETT’S DUMP BLOOMINGTON, INDIANA

Prepared for:

CBS Corporation Bloomington Project

11 Stanwix Street Pittsburgh, Pennsylvania 15222-1384

Prepared by:

PSARA Technologies, Inc. 10925 Reed Hartman Highway

Suite 220 Cincinnati, Ohio 45242

September 2009 PSARA PN 30500.32

Wedge Quarry Passive Drainage System ii Bennett’s Dump, Bloomington, Indiana September 2009

T A B L E O F C O N T E N T S

Section 1: Introduction 1.1 Project Objectives ............................................................................................. 1

Section 2: Facility Description 2.1 Modeling Software............................................................................................ 2 2.2 Watershed Delineation...................................................................................... 2 2.3 Hydrographs...................................................................................................... 2 2.4 Drainage Pipe Design ....................................................................................... 3

List of Tables

Table 1. Modeling Design Parameters

List of Figures

Figure 1. Site Location Map Figure 2. Site Map Figure 3. 5-yr, 24-hr Reservoir Routing

Attachments ATTACHMENT A: EaglePoint Output, Unit Hydrograph ATTACHMENT B: EaglePoint Output, 5-yr 24-hr Computed Flood Hydrograph ATTACHMENT C: EaglePoint Output, Outlet Structure and Reservoir Routing

Wedge Quarry Passive Drainage System 1 Bennett’s Dump, Bloomington, Indiana September 2009

S E C T I O N 1 : I N T R O D U C T I O N The Bennett’s Dump site is located northwest of the town of Bloomington, Indiana, in Monroe County, Indiana (Figure 1). The site is located in a former quarry area where limestone blocks were removed as building stone. It is situated in a wooded area characterized by exposed, water-filled, former limestone quarries. The objective or this project was to perform storm water flow modeling to assist in the design of a passive drain that will lower water levels in existing quarries at the Bennett’s Dump site.

Wedge Quarry Passive Drainage System 2 Bennett’s Dump, Bloomington, Indiana September 2009

S E C T I O N 2 : S T O R M W A T E R M O D E L I N G The goal of the passive drainage system at the Bennett’s Dump site is to lower the water level in all quarries upstream of the site to below a specified elevation. Piping will be installed to connect South Wedge Quarry and Pit “A”. Figure 2 is a site layout map showing the planned locations of pipes connecting the quarries.

2.1 Modeling Software Storm water modeling was performed using Eagle Point 2001 software (revision 1.3.0). Eagle Point offers a storm water modeling module that works in conjunction with computer aided drafting (CAD) software. AutoCAD 2002 was used as the drafting software for this project. The storm water modeling module is capable of creating unit hydrographs, computing flood hydrographs, reservoir routing information, and channel routing.

2.2 Watershed Delineation Watershed delineation was the first step in generating a storm water model for the Bennett’s Dump site. This was accomplished by using topographical data and information gathered through connectivity quarry pump tests. The watershed delineated for a discharge point at Wedge Quarry South includes Pit “A”. This includes 23.5 acres of woods/forest and quarries. Input information used for the development of the storm water model is shown in Table 1. The delineated watershed is shown in Figure 2.

2.3 Hydrographs In the storm water module, the unit hydrograph was constructed using the watershed area and determining a curve number. The watershed area was input as 23.5 acres with a curve number of 58. The SCS curvilinear method was used incorporating the TR-55 method of determining the time of concentration to generate the unit hydrograph. The unit hydrograph is included in Attachment A. The computed flood hydrograph was developed using the site-specific unit hydrograph. The computed flood hydrograph is useful for determining the hydrograph for a specified rainfall event. It was determined that the 5-year, 24-hour storm would be an adequate design for the passive drainage system. The SCS type II rainfall distribution graphs were used to determine rainfall amounts for design storms for Bloomington, Indiana. The 24-hour rainfall amount for the 5-yr storm event was determined to be 3.8 inches. The 5-yr, 24-hr computed flood hydrograph is in Attachment B.

Wedge Quarry Passive Drainage System 3 Bennett’s Dump, Bloomington, Indiana September 2009

2.4 Drainage Pipe Design In the storm water module, the quarry information and the outlet structure (quarry drainage piping) were added. With the use of reservoir routing, the design storm was used to size the quarry drainage pipe and evaluate the water levels in the quarry. It was determined that a 36-inch pipe installed at 736.5 ft elevation in Wedge Quarry South would be capable of keeping the water level below 737.03 ft in the 5yr, 24-hr storm event. The outlet structure information and reservoir routing data, including quarry water levels, are included in Attachment C. Figure 3 shows the 5-yr, 24-hr reservoir routing graph.

TABLES

Table 1. Summary of Storm Water Modeling Design Parameters Wedge Quarry Passive Drain System

Bennett’s Dump Bloomington, Indiana

PARAMETER VALUE Reference

Model/Version Used Eagle Point 2001, revision 1.3.0, Storm Water Modeling Module

Run Date September 17, 2009 Design Storm Scenario 5-year, 24-hour storm 5-year 24-hour Rainfall 3.8 inches Drainage Basin Area 23.5 acres See Figure 2 Curve Number

58- Woods and Forest. Fair to good, Hydraulic Soil Group “B”

Infiltration Rate 0.15 to 0.30 in/hr (wet), Group “B” soil Basin Surface Area (Wedge Quarry South & Wedge Quarry)

29,164 Sq. Ft.

Pipe 36-inch Round N-12 Corrugated Pipe Manning Number 0.012 Pipe Length 260 feet Slope 2.0% Inlet elevation 736.5 ft Outlet Elevation 731.3 ft

FIGURES

ATTACHMENT A

Eagle Point, Unit Hydrograph

ATTACHMENT B

Eagle Point, 5-yr 24-hr Computed Flood Hydrograph

ATTACHMENT C

Eagle Point, Outlet Structure and Reservoir Routing