Total Suspended Solids (TSS) Reduction

Presenter: Keith Noble, Saginaw Bay District OfficePresenter: Keith Noble, Saginaw Bay District Office

A compliance assistance document A compliance assistance document is available on the MS4 websiteis available on the MS4 website

Reduce suspended solid Reduce suspended solid dischargesdischarges

Total Suspended Solids Total Suspended Solids ReductionReduction

Permits require reduction of TSS Permits require reduction of TSS Jurisdictional Permit - Maximum Jurisdictional Permit - Maximum Extent Practicable with a Goal of 25% Extent Practicable with a Goal of 25% reductionreduction

Watershed Permit – Maximum Extent Watershed Permit – Maximum Extent Practicable (?% reduction)Practicable (?% reduction)

Total reduction from the whole systemTotal reduction from the whole system

Reduction from paved surfaces to surface Reduction from paved surfaces to surface waters as compared to annual loading from waters as compared to annual loading from runoff with no suspended controls.runoff with no suspended controls.

Includes:Includes:Streets, roads and highwaysStreets, roads and highwaysParking lotsParking lotsOther impervious surfacesOther impervious surfaces

Permits also require:Permits also require:

Reduction in dust and Reduction in dust and suspended solids from suspended solids from unpaved surfacesunpaved surfaces

Reduce the discharge Reduce the discharge of other pollutants of other pollutants from impervious from impervious surfaces surfaces Salt and Sand for Salt and Sand for

improved tractionimproved traction Petroleum productsPetroleum products

TSS Reduction can be TSS Reduction can be achieved by a combination achieved by a combination

of the following:of the following:

Pollution Prevention - Improved Material HandlingPollution Prevention - Improved Material Handling

Pollution Prevention- Street Sweeping Pollution Prevention- Street Sweeping

Cleaning Catch BasinsCleaning Catch Basins

Catch Basin InsertsCatch Basin Inserts

Pollution Prevention - TreatmentPollution Prevention - Treatment

Settling (Wet Detention Pond)Settling (Wet Detention Pond)

TreatmentTreatmentFiltrationFiltration

Vegetated BufferVegetated Buffer

Filter BermFilter Berm

Filter Berm at Filter Berm at stream crossingstream crossing

Treatment Treatment InfiltrationInfiltration

BioswalesBioswales

Retention PondsRetention Ponds

Removal efficiencies of Removal efficiencies of BMPs assumes that:BMPs assumes that:

Installed Installed according to according to product product specificationsspecifications

Built according to Built according to design criteriadesign criteria

Are adequately Are adequately maintainedmaintained

TSS ReductionTSS Reduction Reduction of sediment from activities Reduction of sediment from activities

already regulated shall not be already regulated shall not be counted toward the TSS reduction.counted toward the TSS reduction.

Regulated activities include:Regulated activities include:

•Construction sites regulated Construction sites regulated under the Part 91 Soil Erosion under the Part 91 Soil Erosion and Sedimentation Control and Sedimentation Control ProgramProgram

•Facilities regulated by the Facilities regulated by the industrial storm water industrial storm water programprogram

First Progress ReportFirst Progress Report Describe current level of controlDescribe current level of control Estimate load reduction from existing Estimate load reduction from existing

controls (Perform TSS calculations)controls (Perform TSS calculations)

TSS reduction to be reportedTSS reduction to be reported

Second Progress Second Progress ReportReport

Evaluate effectiveness of Evaluate effectiveness of current practices (TSS current practices (TSS calculations)calculations)

Identify methods for Identify methods for improving effectiveness improving effectiveness or to achieve 25% goalor to achieve 25% goal

To be implemented in To be implemented in 20132013

TSS reduction to be TSS reduction to be reportedreported

Mean TSS Runoff values for several Mean TSS Runoff values for several land usesland uses

TSS TSS ConcentrationConcentration

Land Use Category Land Use Category (Paved surfaces)(Paved surfaces) Mean mg/l Mean mg/l Mean lbs/ftMean lbs/ft33

High Density Residential High Density Residential 9797 0.00610.0061

Commercial Commercial (Parking Lots, Sidewalks)(Parking Lots, Sidewalks) 7777 0.00480.0048

Industrial Industrial (Fleet Maintenance, Storage (Fleet Maintenance, Storage Yards)Yards)

149149 0.00930.0093

Highway Highway (Roads, Streets, etc.)(Roads, Streets, etc.) 141141 0.00880.0088Adapted from “Rouge River Wet Weather demonstration Project, Adapted from “Rouge River Wet Weather demonstration Project, Selection of Storm Water Pollutant Loading Factors” RPO-MOD-Selection of Storm Water Pollutant Loading Factors” RPO-MOD-

TM34.00, October 1994, Table 3-13TM34.00, October 1994, Table 3-13

(To convert mg/l to lbs/ft(To convert mg/l to lbs/ft33, multiply by 6.243 X 10, multiply by 6.243 X 10-5)-5)

Calculating TSS ReductionCalculating TSS Reduction

Calculating TSS ReductionCalculating TSS Reduction

Step 1- Determine the uncontrolled load for Step 1- Determine the uncontrolled load for each facility. TSS lbs/fteach facility. TSS lbs/ft33 is taken from the is taken from the table on TSS runoff values for land uses.table on TSS runoff values for land uses.

TSS in lbsTSS in lbs X X Precipitation in feetPrecipitation in feet X area of pavement in ft2 = TSS X area of pavement in ft2 = TSS poundspounds ft3 year yearft3 year year

TSS load for 20 miles of road Precipitation = 32 inches = 2.7 ftTSS load for 20 miles of road Precipitation = 32 inches = 2.7 ft

(0.0088 lbs/ft3)(2.7 ft/year)[(20 miles)(25 ft)(5280 ft/mile)] = 62,726 (0.0088 lbs/ft3)(2.7 ft/year)[(20 miles)(25 ft)(5280 ft/mile)] = 62,726 lbs/yearlbs/year

Step 2 - Add up the uncontrolled load for Step 2 - Add up the uncontrolled load for each paved surface that discharges to the each paved surface that discharges to the MS4.MS4.

Load from:Load from:

20 miles of residential roads = 62,726 lbs20 miles of residential roads = 62,726 lbs

1 acre municipal parking lots = 565 lbs1 acre municipal parking lots = 565 lbs

10,000 ft10,000 ft22 paved surfaces at parks = 165 lbs paved surfaces at parks = 165 lbs

20,000 ft20,000 ft22 paved surfaces at DPW = 502 lbs paved surfaces at DPW = 502 lbs

Total for all paved surfaces = 63,958 lbsTotal for all paved surfaces = 63,958 lbs

Calculating TSS Calculating TSS ReductionReduction

Step 3 – Select the BMPs for each site Step 3 – Select the BMPs for each site and calculate the TSS removed, after and calculate the TSS removed, after implementation, for each site based on implementation, for each site based on the chosen BMPsthe chosen BMPs Use BMPs already in place or under consideration Use BMPs already in place or under consideration Removal efficiencies can be found on data basesRemoval efficiencies can be found on data bases Use appropriate efficiency numbers that are Use appropriate efficiency numbers that are

defensible defensible

Uncontrolled TSS load X BMP efficiency for type of paved Uncontrolled TSS load X BMP efficiency for type of paved area = TSS reduction for type of paved areaarea = TSS reduction for type of paved area

Calculating TSS Calculating TSS ReductionReduction

Suspended Solids Removal Efficiency of Select BMPs

Treatment Method

Median Suspended Solids Removal Efficiency (%)

Dry Detention1 49 Wet Detention1 80 Wetland1 72 Filter Practices1 86 Bioretention1 59 Permeable Pavement2 95 Infiltration1 89 Grass Channel2 68 Dry Swale2 93

Calculating TSS Calculating TSS ReductionReduction

TSS Removal Efficiency TSS Removal Efficiency of Select BMPsof Select BMPs

Treatment MethodTreatment Method Median Suspended Median Suspended Solids Removal Solids Removal Efficiency (%)Efficiency (%)

Dry DetentionDry Detention 4949

Wet DetentionWet Detention 8080

TSS Removal EfficiencyTSS Removal Efficiency

Use Actual Amount Removed for:Use Actual Amount Removed for:

Street SweepingStreet Sweeping Catch Basin CleanoutCatch Basin Cleanout Sediment Removed from catch basin insertsSediment Removed from catch basin inserts

Efficiency Dependent upon:Efficiency Dependent upon:

LoadingsLoadings EquipmentEquipment FrequencyFrequency

Example 1Example 110 miles of roads with open channels 10 miles of roads with open channels (vegetated ditches next to roads without curbs) (vegetated ditches next to roads without curbs) 31,363 lbs (.68 for open channels BMP) =31,363 lbs (.68 for open channels BMP) =

21,327 lbs removed21,327 lbs removed Example 2Example 2

Sediment picked up from 10 miles of street sweeping Sediment picked up from 10 miles of street sweeping on curbed streets that were swept twice during the on curbed streets that were swept twice during the year (To determine the number of cubic yards of year (To determine the number of cubic yards of sediment from street sweeping, multiply the number sediment from street sweeping, multiply the number of ydof yd33 by lbs/yd by lbs/yd33

(actual sediment removed from streets)) =(actual sediment removed from streets)) = 10,000 lbs removed10,000 lbs removed

BMP Removal EfficiencyBMP Removal Efficiency

Example 3Example 3Vegetative filters at parks (lawns)Vegetative filters at parks (lawns)165 lbs (.86 for Vegetative Buffers) =142 lbs 165 lbs (.86 for Vegetative Buffers) =142 lbs removedremoved

Example 4Example 4Sediment removed from catch basin inserts at DPWSediment removed from catch basin inserts at DPW(actual sediment taken from catch basin inserts) =(actual sediment taken from catch basin inserts) =

450 lbs removed450 lbs removed

Example 5Example 5Dry detention basin at Municipal parking lotDry detention basin at Municipal parking lot565 lbs (.49 for Dry Detention Basin) = 277 lbs 565 lbs (.49 for Dry Detention Basin) = 277 lbs removedremoved

BMP Removal EfficiencyBMP Removal Efficiency

Step 4 - Add up the calculated load removal Step 4 - Add up the calculated load removal for each site that discharges in the MS4 area for each site that discharges in the MS4 area and the actual amounts removed from catch and the actual amounts removed from catch basin cleanout, street sweeping and catch basin cleanout, street sweeping and catch basin inserts. This is the TSS removed from basin inserts. This is the TSS removed from the system after BMP implementation.the system after BMP implementation.

Roads with open channels BMP Roads with open channels BMP = 21,327 lbs = 21,327 lbs removed removed

Sediment from street sweeping Sediment from street sweeping = 10,000 lbs removed= 10,000 lbs removed

Parks with vegetative buffersParks with vegetative buffers = 142 lbs removed= 142 lbs removedSediment from catch basin inserts Sediment from catch basin inserts = 450 lbs removed= 450 lbs removedParking lot with dry detention basin Parking lot with dry detention basin = 277 lbs removed= 277 lbs removed

Total TSS removed Total TSS removed = 32,196 lbs= 32,196 lbs

32,196 pounds of sediment are 32,196 pounds of sediment are not discharged to the receiving watersnot discharged to the receiving waters

Step 5 – Divide the sum of the TSS Step 5 – Divide the sum of the TSS removed from the system, after BMPs removed from the system, after BMPs are applied, by the sum of the loading are applied, by the sum of the loading from the system, before BMPs are from the system, before BMPs are applied.applied.

Sum of TSS removed with BMPsSum of TSS removed with BMPs = = 32,196 lbs32,196 lbs Sum of TSS load without BMPs 63,958 lbsSum of TSS load without BMPs 63,958 lbs

63,958 lbs – 32,196 lbs = 31,762 lbs63,958 lbs – 32,196 lbs = 31,762 lbs

TSS load TSS load w/out BMPsw/out BMPs

TSS removed TSS removed w/ BMPsw/ BMPs

-- == Treated TSS loadTreated TSS load

31,762 lbs of sediment is31,762 lbs of sediment isdeposited into the receiving watersdeposited into the receiving waters

Step 6 – The result, times 100, Step 6 – The result, times 100, is the percentage reductionis the percentage reduction

((Sum of TSS load with BMPs Sum of TSS load with BMPs ) ) X 100 = % TSS X 100 = % TSS ReductionReduction Sum of TSS load without BMPs Sum of TSS load without BMPs

32,196 lbs32,196 lbs x 100 = 50.3% TSS x 100 = 50.3% TSS reducedreduced

63,958 lbs63,958 lbs

Percent TSS reduction is 50.3 %Percent TSS reduction is 50.3 %

Existing practices (BMPs) already in Existing practices (BMPs) already in place within the MS4 may achieve the place within the MS4 may achieve the 25% reduction goal.25% reduction goal.

Do existing practices meet the Do existing practices meet the Maximum Extent Practicable standard?Maximum Extent Practicable standard?

Questions?Questions?