Addendum No. 1 - FS 227 33 4230 Stormwater Drains Enclosure 52-53.pdf

STK Architecture, Inc. August 2025

SBC Fire Station 227 33 4230-1 Stormwater Drains

SECTION 33 4230

STORMWATER DRAINS

PART 1 GENERAL

1.01 SECTION INCLUDES

A. Precast concrete catch basins.

B. Frames and grates.

1.02 RELATED REQUIREMENTS

A. Section 03 3000 - Cast-in-Place Concrete.

B. Section 31 2316 - Excavation.

C. Section 31 2323 - Fill and Backfill.

D. Section 33 4211 - Stormwater Gravity Piping.

1.03 REFERENCE STANDARDS

A. ACI CODE-318 - Building Code Requirements for Structural Concrete and Commentary; 2019

(Reapproved 2022).

B. ACI PRC-211.1 - Selecting Proportions for Normal-Density and High Density-Concrete - Guide;

2022.

C. ACI PRC-304 - Guide for Measuring, Mixing, Transporting, and Placing Concrete; 2000

(Reapproved 2009).

D. ACI PRC-305 - Guide to Hot Weather Concreting; 2020.

E. ACI SPEC-301 - Specifications for Concrete Construction; 2020.

F. ASTM C94/C94M - Standard Specification for Ready-Mixed Concrete; 2018.

G. ASTM C478/C478M - Standard Specification for Circular Precast Reinforced Concrete Manhole

Sections; 2020.

H. ASTM C990 - Standard Specification for Joints for Concrete Pipe, Manholes and Precast Box

Sections Using Preformed Flexible Joint Sealants; 2009 (Reapproved 2014).

1.04 ADMINISTRATIVE REQUIREMENTS

A. Coordination: Installation of stormwater drains with piping and other structures.

1. See Section 33 4211 for stormwater gravity piping.

B. Sequencing: Ensure that utility connections are achieved in an orderly and expeditious manner.

1.05 SUBMITTALS

A. See Section 01 3000 - Administrative Requirements for submittal procedures.

B. Product Data: Weight rating for catch basins, drop inlets, trench drains, and frame and grates.

C. Manufacturer's qualification statement.

D. Installer's qualification statement.

E. Manufacturer's Certificate: Certify that products meet or exceed specified requirements.

1.06 QUALITY ASSURANCE

A. Manufacturer Qualifications: Company specializing in manufacturing products specified in this section, with at least three years of documented experience.

B. Installer Qualifications: Company specializing in installing work of the type specified in this section, and with at least three years of documented experience and approved by manufacturer.

C. Perform work of this section in accordance with ACI SPEC-301 and ACI CODE-318.

D. Follow recommendations of ACI PRC-305 when concreting during hot weather.

Enclosure #52 Fire Station #227 11/17/25

STK Architecture, Inc. August 2025

SBC Fire Station 227 33 4230-2 Stormwater Drains

PART 2 PRODUCTS

2.01 MANUFACTURERS

A. Drop Inlets:

1. Pre-cast concrete Drop Inlet Catch Basins, sizes as shown on the construction plans.

Products must be approved equal and meet or exceed H-20 load rating, ASTM C478/C478M compliance, wall and base thickness, and joint sealant requirements (ASTM C990).

2. Substitutions: See Section 01 6000 - PRODUCT REQUIREMENTS. Products must be approved equal and meet or exceed the performance, material, load, and dimensional requirements indicated on the drawings and in these specifications.

2.02 CATCH BASINS

A. Weight Rating: H-20 according to AASHTO HB.

B. Precast Concrete Catch Basins: Comply with ASTM C478/C478M.

1. Wall Thickness: According to manufacturer’s specifications.

2. Base Thickness: According to manufacturer’s specifications.

3. Joint Sealant: Comply with ASTM C990.

C. Frames and Grates: Steel or cast iron grate, ADA compliant, H-20 rated.

PART 3 EXECUTION

3.01 EXCAVATION AND FILL

A. Hand trim excavation for accurate placement to indicated elevations.

B. Backfill with cover fill, tamp in place and compact, then complete backfilling.

3.02 INSTALLATION

A. Establish elevations and pipe inverts for inlets and outlets as indicated in drawings.

B. Precast Concrete Catch Basins:

1. Install joint sealant uniformly around section lip.

2. Install according to manufacturer’s instructions and in accordance with ASTM

C478/C478M and ASTM C990, ensuring plumb, alignment, and elevation per drawings.

C. Grade Adjustments:

1. Grade adjustments may use precast risers or masonry units, per manufacturer’s recommendations, to achieve final elevation.

2. Place adjacent materials tight and smooth following design grades.

D. Frames and Grates:

1. Place frame plumb and level.

2. Mount frame on prefabricated drop inlets or trench drains according to manufacturer's instructions.

3. Place grate in frame securely.

END OF SECTION

Enclosure #53 Fire Station #227 11/17/25

B. Sequencing: Ensure that utility connections are achieved in an orderly and expeditious manner.

C. Frames and Grates: Steel or cast iron grate, ADA compliant, H-20 rated.