Information on cost and maintenance for implementing a street sweeping program is variable. This is due to several factors, including but not limited to equipment cost and maintenance, frequency of sweeping, operator skills, and disposal methods.

## Cost information

Data compiled from the case studies in this manual are illustrated in the adjacent table. The median cost per curb mile is $94 while the mean cost is$487, showing the wide variation in cost information. The cost information provided by the cities typically does not include equipment costs but typically does include disposal costs.

Three cities from the case studies (Mankato, St. Cloud, Roseville) reported information on mass or volume of material collected. We used the Street Sweeping Phosphorus Credit Calculator to estimate cost per pound of phosphorus removed. We used the wet mass method and calculated values for fall and for the remainder of the year.

• Mankato: Cost ranged from $293-408 per pound of phosphorus • St. Cloud: Assuming a bulk density of 0.11 kg/L for material collected ([1]), cost ranged from$174-243 per pound of phosphorus. The City estimates the cost as $195-246/lb-P over a period of four years, with a median cost of$226/lb-P.
• Roseville: Cost ranged from $85-119 per pound of phosphorus. The City estimated$193/lb-P in their calculations.

The City of Prior Lake and University of Minnesota researchers conducted an intensive study of street sweeping in Prior Lake (Kalinosky et l., 2014). This study included a literature review of other sweeping studies. Cost per mile swept was computed on a monthly basis and ranged from $20-29 per mile. This is similar to the cost data reported by Mankato and St. Cloud, which were the two best documented case studies. Cost effectiveness of sweeping was$41-lb-P in October, less than $100/lb-P during March, April, October, and November, and$400-600/lb-P in the summer months. While tree canopy and cost effectiveness were correlated, other factors such as particle size of solids affected the cost effectiveness of sweeping.

A discussion of cost consideration can be found at this link.

Cost information for cities from street sweeping case studies
City Annual cost (\$) Curb miles swept Cost per curb mile
Lakeville 246000 1200 205
Mankato 400000 11814 34
Rochester 80000 11000 7
St. Cloud 70000 1825 38
Bloomington 850000 342 2485
Fridley 225000 1500 150
Costs typically do not include sweeper replacement cost

## Comparison of cost effectiveness of street sweeping with other stormwater best management practices

There is considerable variability in cost effectiveness of different stormwater practices. Some studies show street sweeping to be ineffective for phosphorus removal compared to other practices, while other studies indicate sweeping is highly cost effective. A challenge in comparing studies is gaining access to specific information for each practice. In the case of street sweeping, for example, studies comparing sweeping to other practices rarely provide information about the sweeping practice, such as time of year, type of sweeper, and frequency of sweeping. Another challenge is studies do not contain the same set of bmps, and street sweeping is often not included in these studies. Another concern is that some studies favor specific bmps and therefore the data presented are questionable.

We conducted a cursory review of the literature to get a range of information on cost effectiveness for stormwater practices, including street sweeping.