Publications

Best Management Practices for Chemical Treatment Systems for Construction Stormwater and Dewatering

Previous Chapter « Table of Contents » Next Chapter

FHWA-WFL/TD-09-001
January 2009

Front Materials

• Cover
• Table of Contents
  • Figures
  • Tables
• Acronyms and Abbreviations

 

Technical Report Documentation Page

1. Report No. FHWA-WFL/TD-09-001	2. Government Accession No.			3. Recipient's Catalog No.
4. Title and Subtitle Best Management Practices for Chemical Treatment Systems for Construction Stormwater and Dewatering				5. Report Date January 2009
				6. Performing Organization Code
7. Author(s) Richard A. McLaughlin, Ph.D. and Alex Zimmerman, CPESC				8. Performing Organization Report No.
9. Performing Organization Name and Address North Carolina State University 101 Derieux Street, 2232 Williams Hall Raleigh, NC 27695				10. Work Unit No. (TRAIS)
				11. Contract or Grant No.
12. Sponsoring Agency Name and Address Federal Highway Administration Western Federal Lands Highway Division 610 East 5th St. Vancouver, WA 98661				13. Type of Report and Period Covered Final Report 2009
				14. Sponsoring Agency Code HFL-17
15. Supplementary Notes COTR: Amit Armstrong, Ph.D., P.E. This project was funded under the FHWA Federal Lands Highway Technology Deployment Initiatives and Partnership Program (TDIPP) and Coordinated Technology Implementation Program (CTIP).
16. Abstract Chemical treatment systems (CTS) are implemented in areas where traditional, physical erosion and sediment control practices will not meet water quality goals for construction site runoff. The purpose of CTS is to reduce the amount of suspended sediment which would be released using conventional erosion control systems. The primary mechanism is the introduction of chemical flocculants into runoff, resulting in a binding of the suspended clays and silts together into larger particles which settle more quickly or can be filtered from the stormwater. Flow control through CTS is of vital importance for the proper dosing of stormwater runoff. All normal hydrologic analyses must be done to insure that reasonable peak flows are accounted for along with typical flows from designed storm events. Once analysis is adequately addressed, then the project can deal with the complexities of design and dose rate requirements. The overall objectives of this book are twofold. First, it is designed to provide a technically credible basis for best management practices for the use of CTS for turbidity reduction on road construction projects. Secondly, it is designed to identify the most important variables to address when selecting chemical treatment best management practices for a particular site.
17. Key Words BEST MANAGEMENT PRACTICES, CHEMICAL TREATMENT SYSTEMS, STORMWATER, DEWATERING, WATER QUALITY, TURBIDITY			18. Distribution Statement No restriction. This document is available to the public from the sponsoring agency at the website https://flh.fhwa.dot.gov/.
19. Security Classif. (of this report) Unclassified		20. Security Classif. (of this page) Unclassified			21. No. of Pages 12	22. Price $0.00

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

Table of Contents

SI* (MODERN METRIC) CONVERSION FACTORS
APPROXIMATE CONVERSIONS TO SI UNITS
Symbol	When You Know	Multiply By	To Find	Symbol
LENGTH
in	inches	25.4	Millimeters	mm
ft	feet	0.305	Meters	m
yd	yards	0.914	Meters	m
mi	miles	1.61	Kilometers	Km
AREA
in2	square inches	645.2	Square millimeters	mm2
ft2	square feet	0.093	Square meters	m2
yd2	square yard	0.836	Square meters	m2
ac	acres	0.405	Hectares	ha
mi2	square miles	2.59	Square kilometers	km2
VOLUME
fl oz	fluid ounces	29.57	Milliliters	mL
gal	gallons	3.785	Liters	L
ft3	cubic feet	0.028	cubic meters	m3
yd3	cubic yards	0.765	cubic meters	m3
NOTE: volumes greater than 1000 L shall be shown in m3
MASS
oz	ounces	28.35	Grams	g
lb	pounds	0.454	Kilograms	kg
T	short tons (2000 lb)	0.907	megagrams (or "metric ton")	Mg (or "t")
TEMPERATURE (exact degrees)
°F	Fahrenheit	5 (F-32)/9 or (F-32)/1.8	Celsius	°C
ILLUMINATION
fc	foot-candles	10.76	Lux	lx
fl	foot-Lamberts	3.426	candela/m2	cd/m2
FORCE and PRESSURE or STRESS
lbf	poundforce	4.45	Newtons	N
lbf/in2	poundforce per square inch	6.89	Kilopascals	kPa
APPROXIMATE CONVERSIONS FROM SI UNITS
Symbol	When You Know	Multiply By	To Find	Symbol
LENGTH
mm	millimeters	0.039	Inches	in
m	meters	3.28	Feet	ft
m	meters	1.09	Yards	yd
km	kilometers	0.621	Miles	mi
AREA
mm2	square millimeters	0.0016	square inches	in2
m2	square meters	10.764	square feet	ft2
m2	square meters	1.195	square yards	yd2
ha	Hectares	2.47	Acres	ac
km2	square kilometers	0.386	square miles	mi2
VOLUME
mL	Milliliters	0.034	fluid ounces	fl oz
L	liters	0.264	Gallons	gal
m3	cubic meters	35.314	cubic feet	ft3
m3	cubic meters	1.307	cubic yards	yd3
MASS
g	grams	0.035	Ounces	oz
kg	kilograms	2.202	Pounds	lb
Mg (or "t")	megagrams (or "metric ton")	1.103	short tons (2000 lb)	T
TEMPERATURE (exact degrees)
°C	Celsius	1.8C+32	Fahrenheit	°F
ILLUMINATION
lx	lux	0.0929	foot-candles	fc
cd/m2	candela/m2	0.2919	foot-Lamberts	fl
FORCE and PRESSURE or STRESS
N	newtons	0.225	Poundforce	lbf
kPa	kilopascals	0.145	poundforce per square inch	lbf/in2

• List of Acronyms
• 1. Introduction
• 2. Rationale for Choosing Chemical Treatment Systems (CTS)
• 3. Design for CTS
  • 3.1 Approvals
  • 3.2 Criteria for Chemical Treatment Product Use
  • 3.3 Treatment System Design Elements
  • 3.4 Sizing Criteria
  • 3.5 Location of CTS
• 4. Stormwater Treatment (Use of CTS)
  • 4.1 Inspection and Maintenance
  • 4.2 Discharge Compliance
  • 4.3 Operator Training
  • 4.4 Standard BMPs
• 5. Maintenance And Decommissioning
  • 5.1 Sediment Removal and Disposal
  • 5.2 Adjustment of Settling and Retention Pond
  • 5.3 Remove All Equipment and Chemicals from the Site and Store in a Safe Manner
• 6. Monitoring Report of Chemical Treatment Systems
• References
• Appendix A: List of Chemicals Typically Used for Treating Turbidity
  • Appendix A: Polymers
  • Appendix A: Other Additives
• Appendix B: Examples of Chemical Treatment Systems and Costs
  • Appendix B: Estimating Total Monthly System Costs Based on Three Reasonable Scenarios

Figures

• Figure 1: Chemical Treatment System Schematic Using Mobile Tank for Pretreatment
• Figure 2: Chemical Treatment System Schematic Using a Detention Basin for Pretreatment
• Figure 3: Chitosan Enhanced Sand Filtration with Batch Treatment
• Figure 4: Example of a Simple Chemical Treatment System Using a Stilling Basin
• Figure 5: Example of a Simple Chemical Treatment System
• Figure 6: Example of a Passive Dosing Chemical Treatment System
• Figure 7: Example Layout of a Chemical Treatment System on a Construction Site

Tables

• Table 1: 240,000 gpd Chitosan-Enhanced Sand Filter System Costs (Winter 2007)
• Table 2: Once Only Costs - Does Not Include Physical Site Preparation
• Table 3: Hard Recurring Monthly Costs
• Table 4: Variable Monthly Costs
• Table 5: Scenario One
• Table 6: Scenario Two
• Table 7: Scenario Three

List of Acronyms

BMPs - Best management practices

CTS - Chemical treatment systems

DADMAC - Diallyldimethyl ammonium chloride

EPA - Environmental Protection Agency

ESC - Erosion and sediment control

NPDES - National Pollutant Discharge Elimination System

NTU - Nephelometric Turbidity Unit

PAM - Polyacrylamide

SWPPP - Stormwater Pollution Prevention Plan

TSS - Total Suspended Solids

Previous Chapter « Table of Contents » Next Chapter