Traction sand. Spillage- Septic waste, plastics. Metal Salts, pure metals carbonates

Transcription

1 Street Sweeping as a method to reduce surface water pollution June 30, 2010

2 Let s start with how pollution can get from the street to the water, where the pollution came from and what it might contain

3 Traction sand Spillage- Septic waste, plastics Metal Salts, pure metals carbonates

4 Car Parts-Heavy metals, plastics, Iron Construction Silt

5 I think we all know how it gets there But: it s not supposed to

6 How does the volume of pollution from the street compare to other non point sources? We don t know! What is the quantity of toxins in the street dirt? We don t know!

7 We have anachdotal reports that when tested, street dirt is not considered hazardous waste. My go to normal landfill May be recycled Common sense exceptions to the above Industrial processing plants may produce toxic sweeping debris

8 For construction sites It s a Federal statute! Remove any sediment or other pollutants, including construction materials, from paved surfaces daily. Submitted for publication in the Federal register on November For many municipalities it s how they got their discharge permits! Good housekeeping Number 6 from the EPAs minimum control measures

9 Many Cities like Denver CO require sweeping with in 4 days after every snow event Regulation No. 16 Street Sanding Emissions This statute is actually aimed at air pollution, but imagine how much doesn t get to the surface water

10 Besides the obvious litter, what is this stuff we have to remove to prevent storm water runoff pollution?

11 It s called silt It s basically ground up inorganic stuff <80 micron in diameter It s small so it wants to stay in solution Vehicle traffic and rain turn bigger stuff in to silt by grinding it up and dissolving the binder that holds the smaller pieces together Silt can be the transport vehicle for chemical pollutants as well as being a pollutant it self.

12 Street dirt fun facts 80% of the typical silt, or debris that could become silt, is located within. several feet of the gutter The typical deposition amount of total material is about 1000 lbs per curb mile. The 1000 lbs will re-deposit in as fast as two weeks.

13 How much road dirt does sweeping remove? I am glad you asked- A series of tests recently run by Pacific Water Resources indicate that:

14 We remove almost all of it.! 100 Sweeper Pickup Efficiency vs Particle Size Pacific Water Resources (%) Efficiency ( FW 91.5% FW+W 81% MV 93.5% 30 CW 96.4% NX 97.5% < Particle Size (microns)

15 What is the PWR pickup efficiency test. 1. Average N/A deposition 2. Average N/A sieve mix 3. Controlled tests 4. Probably not perfect but all known end of pipe tests have failed to yield results good or bad

16 How does sweeper technology relate to pickup efficiency at 63 micron? High efficiency regen 98% Standard Regen 96% Pure vac 94% High efficiency mechanical 92% Standard wet dust control 81% mechanical

17 How does sweeper cost relate to technology Traditional Regenerative technology 1 Traditional vacuum technology 1.1 Traditional mechanical technology 1.2 High efficiency mechanical technology 1.35 High efficiency regen technology 1.35 Based on Elgin Sweeper company sweeper list prices Actual life cycle costs are typically not public

18 Is sweeping cost effective for pollution control

19 Pay a little Remove it from the street $5-$10 silt lb

20 Pay a little more Remove it from the catch basin $10-$20 silt lb

21 Pay lots and lots more Remove it from the watershed Don t know-ask BP

22 What we know about sweeping for water Quality Sweeping is a classic pollution prevention technique -- removing pollutants before they enter surface waters Catch basin cleaning works but it is more work and a last chance proposition There is sometimes a lack of understanding about how to use sweepers to prevent water pollution.

23 What we know about sweeping for water Quality Sweeping is a storm water BMP. And the more you sweep, the more is removed. How often per Center for watershed Protection: Once prior to a rain event and once after. If you can t predict the weather or it never rains: Measure your re-deposition rate. Focus on rapid deposition areas. Enforce laws that already exist.

24 What our challenges are going forward Sweeping traditionally was/is to remove visible debris. Public works officials are often judged by how the streets look compared to how much (or little was spent) Modern high efficiency sweepers cost more There is science and proper procedures in sweeping for water pollution control. It s not complex and it s not difficult, but it s different than just making the street pretty. There is a huge amount of misinformation concerning sweeper use and pollution in general.

25 Where do we go from here We must educate the users that water pollution remediation and air pollution remediation require different techniques. We must provide sweeping frequency guidance We must help users understand that street sweeping can be used effectively as a water pollution prevention strategy any situation but the method of sweeping must be optimized for individual applications.

26 Where do we go from here Available resources EPA website Pacific Water Resources. Q&A