As the temperatures fall and the leaves do too, the annual leaf collection programs start operating again. Whether it’s a community drop-off location for bagged leaves, municipally operated trucks, vacuums and sweepers to collect the piles along the road, or something in between, the public expects relatively clear roads and storm drains throughout the fall months. Recent studies have highlighted an additional benefit of fall leaf collection programs: improved water quality in local lakes and streams.
WDNR’s “Interim Municipal Phosphorus Reduction Credit for Leaf Management Programs” (March 2018) allows communities with Municipal Separate Storm Sewer System (MS4) permits to quantify the amount of phosphorus being captured annually through leaf collection programs in certain areas, provided the programs meet the following criteria:
Land use must be medium density residential without alleys.
Storm sewer system must be comprised of curb and gutter with storm sewers. Light parking along these curbs is required during leaf collection and street cleaning operations.
Mature trees should be located approximately every 80 feet within the terrace area, between the sidewalk and the road.
An ordinance must be in place prohibiting residents from placing leaves in the street; piles are allowed to be raked and bagged and left on the terrace behind the curb.
Leaves are to be collected at least 4 times between October and November. Leaves are not to be left in piles in the street overnight.
A street sweeper (mechanical broom or vacuum assisted) is required to follow the leaf collection route within 24 hours to capture the remaining leaf litter.
Communities that meet these requirements in the applicable areas can include 17% phosphorus control in their pollutant loading analysis. This is an important source control practice that communities can now quantify to show progress toward meeting phosphorus reductions in TMDL areas.
It may be more cost-effective to modify the annual leaf collection program in certain areas of a community than to construct multiple new storm water treatment facilities to capture an equivalent 17% of phosphorus from storm water.
Consider the following when determining whether to update a leaf collection program to quantify this phosphorus control activity:
The cost/time involved with passing a new leaf collection ordinance.
The cost/time of updating the leaf collection program to pick up leaves in the medium density residential areas at least 4 times each fall, including staff training, written program updates, and communications to residents.
The cost of renting or purchasing new street sweeper equipment (and potential grant opportunities).
Additional studies are currently underway to characterize the amount of phosphorus being captured from leaf collection programs in different land use and storm sewer system conditions. The results of these studies are expected to be available in 2020 and may offer additional opportunities for municipalities to quantify phosphorus controls through leaf collection activities.
About the Author
Maureen A. McBroom
Senior Water Resources Coordinator
Maureen is dedicated to the protection and improvement of Wisconsin’s resources through close collaboration with municipalities and their citizens. Efficient & effective implementation, driven by strong relationships and communication, are drivers behind her project implementation strategies. She has experience in the WDNR’s Runoff Program, specifically issuing WPDES Permit coverage for construction site erosion control & long-term storm water plans, industrial storm water sites and municipal separate storm sewer system (MS4) permittees. Maureen has been with R/M since 2015.
