Clean sweep: street sweeping, storm water BMPs
The Minnesota Local Road Research Board’s Research Implementation Committee (LRRB-RIC) recently completed helpful resource guides for two ongoing, real-life needs—street sweeping and storm water best management practices (BMPs), said Mike Marti of SRF Consulting. He made his comments at the City Engineers Association of Minnesota (CEAM) annual conference on January 28, 2009.
The goal of the resource guides is to provide easy access, as well as practical, implementable information, Marti said.
Street sweeping
The street-sweeping project, sponsored by Mn/DOT, synthesized recent research to create four information sheets and a PowerPoint presentation about street sweeping best practices. Street sweeping is vitally important for removing trash, atmospheric and vehicle-related pollution, and debris from lawns, construction sites, and roadway wear and tear.
The four information sheets, intended to be used as a group, cover these topics:
- overview of street sweeping
- types of street sweeping equipment and how they operate
- reasons for street sweeping
- the differing agency functions (city, county, and state) in appropriate street sweeping
The information sheets help agencies understand the cost-benefit of various equipment as well as functions and limitations of specific equipment. “We had to balance what the industry said the street-sweeping equipment could do versus what we found out it really could do,” Marti explained.
The guides also help agencies select sweeping frequencies. Study surveys indicated that the frequency of street sweeping in Minnesota was far lower than nationwide averages. Minnesota sweeps two times annually, in spring and fall, while the average was 10 times each year. “Minnesota does its street sweeping for aesthetic reasons while other states did it for storm water quality issues,” Marti said.
The guides also include a decisionmaking process and policies to help agencies create the most efficient operations for their area. The handy format also makes the information easy to present to city councils with budget justifications. Overall, Marti said, the guides “will help agencies that want to move toward better management practices and newer technologies for green pavement.” Kathy Schaefer, the instructor of the Circuit Training and Assistance Program (CTAP), uses the guides in her training. (CTAP is the mobile arm of Minnesota LTAP.)
To read a technical summary of the project, please see www.lrrb.org/detail.aspx?productid=2254. To download the guidelines (report 2008RIC06), see www.lrrb.org/detail.aspx?productid=2159.
Storm water quality
Also at the CEAM conference, Mark Maloney of the City of Shoreview provided an overview of storm water quality BMPs—the topic of the second new LRRB guide. The guide, due out later this year (www.lrrb.org), defines and describes BMPs and provides inspection forms that users can modify to meet the needs and special purposes for storm water management techniques in local areas. The guide covers BMPs for storm water ponds, bio-retention areas, underground treatment devices, underground retention, infiltration, and newer storm water quality techniques that are just being introduced.
A major benefit of the information is help in determining benefits and limitations of each method, “aimed at helping the end user who needs to budget and schedule inspection and maintenance,” Maloney said. Maintenance forms are included to help assess if each storm water management technique is functioning properly, and the point at which it needs cleaning or replacement.
The purpose of the guide is not to promote one BMP over another. “We hope the guide will influence design decisions once people start using the checklists and doing proper evaluations of their BMP performance,” Maloney concluded.
— Jeanne Engelmann, LTAP freelancer