Webcast Agenda 5/28/2014. Speaker Info. Chesapeake Bay Stormwater Training Partnership. Welcome to the Webcast. The Real Dirt!

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1 Welcome to the Webcast Advanced Stormwater Design Webcast Series: The Real Dirt! To Ask a Question Submit your question in the chat box located to the left of the slides. We will answer as many as possible during Q&A. To Answer a Poll Question Simply select the preferred option. For those viewing this session alongside several colleagues, respond in a manner that represents your organization as a whole. We ARE Recording this Session All comments and questions will be recorded and included in the archives. We will notify you as soon as the recording and related resources are loaded on the web. We Appreciate Your Feedback Fill out our evaluations our funders need to hear it! Speaker Info Chesapeake Bay Stormwater Training Partnership Visit: Dr. Shirley Clark, Penn State Harrisburg, sec16@psu.edu Deb Caraco, Center for Watershed Protection dsc@cwp.org Dave Hirschman, Center for Watershed Protection, djh@cwp.org Cecilia Lane, Chesapeake Stormwater Network, watershedgal@hotmail.com To learn how you can have access to: Discounted Webcasts Free One-day design workshops Intensive master stormwater design seminars Direct On-site technical assistance Self guided web-based learning modules CSN s 2014 Webcast Series No. Date Series Topic 2 March 27 Advanced Stormwater Design Bioretention & Dry Swales 3 April 3 Advanced Stormwater Design Permeable Pavement 4 April 24 MS4 Implementers and the Bay TMDL Stream Restoration 5 May 1 Advanced Stormwater Design Infiltration 6 May 8 MS4 Implementers and the Bay TMDL Urban Nutrient Management 7 May 27 Advanced Stormwater Design The Real Dirt! (Soils and Soil Amendments) 8 May 29 MS4 Implementers and the Bay TMDL Enhanced Erosion and Sediment Control Measures 9 June 5 Advanced Stormwater Design Constructed Wetlands 10 June 12 Advanced Stormwater Design Rainwater Harvesting 11 June 26 Advanced Stormwater Design Filter Strips & Disconnections Webcast Agenda Introduction to Soils Soil Testing Methods Soil Restoration Techniques Soil Amendments as a BMP in the Bay watershed 1

2 Poll Question #1 How many people are watching with you today? Just me 2-5 people 6-10 people > 10 people Poll Question #2 Tell us a little about yourselves who are you representing today? Design professional MS4 Phase 1 MS4 Phase 2 State government Federal government Other Poll Question #3 What is your experience or interest with soils? Why Soil Amendments Could be a Game Changer in the Bay I do infiltration testing I am looking at soil restoration as a possible BMP I like to make mudpies Source: CSN Technical Bulletin No. 8, April 201 LOTS OF TURF = LOTS OF OPPORTUNITY! Why Soil Amendments Could be a Game Changer in the Bay Compacted Disturbed Urban Soils: Challenge & Opportunity Compaction: Essential for Construction Disturbed Compacted Soil follows from standard development practices Result Decouples Form and Function 3 acres of grass for each acre of impervious cover Enormous opportunity to use grass as a better stormwater sponge! Slide Credit: Stu Schwartz, Center for Urban Environmental Research and Education, University of Maryland Baltimore County 2

3 Soil Composition Soil Basics for Stormwater Image Source: salinitymanagement.org Infiltration Testing: Percolation Test (measures subsurface flow rates) Used as a preliminary assessment of soil infiltration. Saturate soil Fill hole with water and measure level at time intervals to determine percolation rate. Infiltration Testing: Infiltration Test (measures surface and near-surface flowrates) Similar methodology of percolation testing Major difference is that infiltration is only through the bottom of the test pit. An infiltrometer or casing is used to prevent percolation through the walls of the test pit. Factors affecting Soil Infiltration /rainfall_infiltration_rate2.gif Texture Crust Compaction Structure Water Content Organic matter Porosity Freezing 3

4 Soil Porosity Soil Texture Is Determined by Particle Size Mixture As soil porosity increases, water can flow more easily through the available pore spaces. Source: Discovery Education Soil Texture and Hydrologic Soil Group (HSG) Hydrologic Soil Group depends on soil texture. Most permeable (A) soils tend to be sandy Least permeable (D) soils are clays. Decreases Bulk Density Organic Matter HSG Determined by (Ref: USDA): Soil composition Permeability of the least transmissive layer of soil Depth to impermeable layer or water table Increases Water Content Available to Plants However all soils can pond water. Sandy Soils Soil Compaction: Loss of Macropores in Soil Profile Clayey Soils 5/28/

5 Impacts of Soil Compaction on Vegetation and Vegetation on Soil Compaction Symptoms of soil compaction on vegetation: Slow growth Small, distorted, sparse, chlorotic and nutrientdeficient e leaves es Scorch Premature autumn color Premature leaf drop Abnormally large "distress" crops of fruit Insufficient storage of food reserves for winter Dieback of twigs or branches. Soils Also Act as a Treatment Medium (TMDL) Load = Volume x Concentration Soils can affect both Soil is Heterogeneous and Each Layer Has Specific BioGeoChemical Properties Soil Chemistry Effects on Design to Be Considered Remove pollutants in the upper layers of the media. The deeper into the soil profile that the pollutants penetrate, the greater the likelihood of groundwater contamination or transport out of the device through an underdrain. Potential properties of interest in predicting removal: Soil and water ph Pollutant forms (relationship to solids loading and PSD) Cation Exchange Capacity (CEC) [and Anion Exchange Capacity (AEC)] Mineral matter Organic content Phosphorus content Oxidizing or reducing environment Salinity and Sodium Adsorption Ratio (SAR) soil/geosoil.htm Slowing Contact Time in Media Increases Pollutant Removal Longer contact times generally result in improved pollutant removal for metals. However, for pollutants that are released from the soil, long contact times result in additional leaching. Must balance treatment time (moderate) and draindown times (short). Influent test water Rhyolite sand Surface modified zeolite Site zeolite Peat moss GAC 29 General Rule of Thumb: For nutrients, if soil is Low, it is more likely to remove nutrients from runoff. If soil is High, leaching more likely. 5

6 Copper Column testing ti breakthrough h capacity = ~ 15 mg/kg Bench-scale batch capacity testing = ~ 45 mg/kg Inability of/insufficient time for metal ions to migrate to inner pore spaces during flow-through operation and therefore, total removal ability of media not used? Transfer of batch testing data to field analysis of capacity problematic. Breakthrough Copper Accumulation in Upper Layers of Soil with Subsequent Downward Migration Limited Release of CEC Cations or Decrease in CECe (sum of K, Ca, Mg) Complexation/chelation /exchange with organic compounds, which is not measured in CECe calculations CECe = sum (K, Ca, Mg) Organic (0 3 layer) Flow as a Function of Solids Loading Infiltration rates typically decrease over a device s life due to solids capture on the surface of and in the media. Want higher initial infiltration rate knowing it will decrease over time. Need to meet draindown requirements just before maintenance. Most media typically fail when the total solids loading is about 10 to 25 kg/m 2 of media surface (flow rate < 1 m/d, generally). Media removal generally more effective maintenance technique, but must remove at least 4 6 because clogging solids are captured deep in the media (deeper than visible solids buildup). Effect of Temperature on Viscosity of Infiltrating Water Recession Rate [in/hr] BTI (4.25 years of data) BioInfiltration Traffic Island seven point moving average best fit periodic function Y = *Sin(X(days)/55) Temp. [C] EMERSON and TRAVER Snow Piles on Bioretention Facilities Snowmelt contains high concentrations of a cation and chloride (Cl - ). Sodium regenerates ion-exchange resins (washing off previously-captured pollutants). Sodium destabilizes clays (measured in sodium-adsorption ratio). Soil Restoration Techniques: Aeration Goals: Increase macropores. Decompact soil. Restore infiltration. Aeration includes the use of machines such as tractor-drawn implements with coulters making a narrow slit in the soil, a roller with many spikes making indentations in the soil, or prongs which function like a mini-subsoiler. Soil Restoration Techniques: Topsoiling Goals: Restore the upper soil horizon (A-Horizon) Create a medium for plant growth. Restore organic matter. 6

7 Soil Restoration Techniques: Compost Amendments Compost shall be aged, from plant derived materials, free of viable weed seeds, have no visible free water or dust produced when handling, pass through a half inch screen and have a ph suitable to grow desired plants. Goals: Restore soil organic material. Improve soil infiltration ti capacity. Provide an environment for plant growth. Redevelopment Full soil restoration required where land is converted from paved to pervious. Infiltration/ Runoff Reduction Areas Not Required Can be applied to improve performance. Q & A Practices that benefit: Vegetated swale Impervious cover disconnection Standard Landscape Development Practices Soils & Stormwater Part of site design, Environmental Site Design State compliance methods (preserving soils, disturbing/compacting soils) Component of BMPs (e.g., soil media) Test for infiltration BMPs As an amendment to enhance runoff reduction & BMP performance Cuyahoga Sustainability Network 7

8 Applications 1. Reduce Runoff Volume From Pervious Areas 2. Enhance Performance of Impervious Disconnection 3. Enhance Performance of Other Runoff Reduction Practices 4. Part of a Reforestation Plan 1. Reduce Runoff Volume From Pervious Areas (NO contributing impervious drainage area) Photo Credit: Jeremy Balousek, P.E., Dane County, WI Land and Water Resources Department 2. Enhance Performance of Impervious Disconnection 3. Enhance Performance of Other Runoff Reduction Practices Vegetated Filter Strip Photo Credit: Jeremy Balousek, P.E., Dane County, WI Land and Water Resources Department Grass Channel 4. Part of a Reforestation Plan NOT Recommended Where: The water table or bedrock is located within 2 feet of the soil surface. Slopes exceed 10%. Existing soils are saturated or seasonally wet (including some soils in Hydrologic Soil Group D). They would harm roots of existing trees (keep amendments outside the tree drip line). The downhill slope runs toward an existing or proposed building foundation. The contributing impervious surface area exceeds the surface area of the amended soils. Areas that will be used for snow storage. 8

9 State Stormwater Performance and BMP Performance Credits Most states established a stormwater treatment volume that must be managed by a BMP; The volume is computed as the amount of runoff generated by a specified rainfall depth; The rainfall depth is defined by each state: DC, MD, NY, VA, & WV: 90 th percentile rainfall depth (approximately 1 inch); DE: Resource Protection Event (RPE) = 2.7 inches of rainfall. Designers should consult the individual state design criteria for guidance on computing the required runoff volume. 49 State Regulatory Performance Standard 1 BMP Performance Credit 1 DC On-site retention of runoff from 1.2 Runoff Volume reduction rainfall DE Zero effective impervious for 2.7 rainfall Runoff Volume Reduction (Resource Protection Event, RPE) MD On-site retention using ESD of runoff Runoff Volume Reduction from 1.0 rainfall NY On-site retention of runoff from 90 th percentile rainfall (~ 1 ) Runoff Volume Reduction PA No increase in total runoff volume for all events up to the two year storm (2.8 ) OR Capture the first 2 of runoff from impervious, with first 1 being removed VA Total Phosphorus Load Limit of 0.41 lbs/ac/yr (performance based on management of runoff from 1.0 rainfall) WV On-site retention of runoff from 1.0 rainfall The State Manual is in flux Total TP Load Reduction (Runoff Volume + Pollutant Removal) Runoff Volume Reduction 1 Some states may include watershed specific pollutant load reduction requirements 50 for select parameters, e.g., TP or TSS, in addition to volume reduction. Increase in Treatment or Storage Volume for Disturbed/Compacted Soils Soil Amendments & Performance (VA): Grass Channels in C/D Soils Bump up Hydrologic Soil Group (HSG) (e.g. B to C) Change land cover (Rv) that results in higher treatment/storage volume More difficult to meet ESD standards Removal Metric WITHOUT WITH AMENDMENT AMENDMENTS Runoff Reduction 10% 20% TP EMC Removal 15% 15% TP Total Mass Removal 24% 32% Soil Amendments & Performance (VA): Impervious Disconnection in C/D Soils Soil Amendments & Performance (VA): Vegetated Filter Strips in B/C/D Soils Removal Metric WITHOUT AMENDMENTS WITH AMENDMENED FILTER PATH Runoff Reduction 25% 50% TP EMC Removal 0% 0% TP Total Mass Removal 25% 50% Removal Metric WITHOUT WITH AMENDMENS AMENDMENTS Runoff Reduction N/A 50% TP EMC Removal N/A 0% TP Total Mass Removal N/A 50% 9

10 Soil Amendment Performance Credit (generally C and/or D soil applications) State Grass Channel Disconnection Filter Strip DC Volume Reduction (Sv): Volume Reduction See Disconnection 10% 30% (Sv): Performance 2 cf 4 cf/100 sf of pervious area DE Volume Reduction (RPv): 10% 20% Volume Reduction (RPv): 10% 25% (C soils) Volume Reduction (RPv): 10% 25% (to turf) 20% 40% (to forest) MD Part of ESD process Part of ESD process Part of ESD process Soil Amendments: Bigger Piece of Pie NY VA WV Required to meet performance standard TP Mass Reduction: 24% 32% Volume Reduction (Tv): /D.A. Required to meet performance standard TP Mass Reduction: 25% 50% Volume Reduction (Tv): 2 cf 4 cf/100 sf of pervious area PA Volume credit as per Specification Required to meet performance standard TP Mass Reduction: N/A 50% Volume Reduction (Tv): 3 cf 6 cf/100 sf of filter strip 55 When Using Soil Amendments to Boost Runoff Reduction From Disturbed/Compacted Areas BUT NO CONTRIBUTING DRAINAGE AREA Hydrologic Soil Group Reduce Rv; Reduce Treatment Volume* Undisturbed Soils Disturbed Soils Soil Amended Soil Amended & Reforested A B C D * Recommended approach based on specifications from various states. Each state may have a different approach. Selected Key Design Issues 1. Soil Testing 1. Soil Testing 2. Depth of Compost Incorporation 3. Compost Specifications 4. Methods to Incorporate Compost Photo Credit: Jeremy Balousek, P.E., Dane County, WI Land and Water Resources Department Photo Credit: Richard McLaughlin, Ph.D., North Carolina State University 59 10

11 Testing: 2 Times During Amendment Process 1. Pre-Amendment Soil Properties Test to 1 foot below proposed amendment depth Bulk density, ph, salts, soil nutrients One test/5,000 square feet Used to determine what amendments are needed 2. After Compost is Incorporated In conjunction with final inspection; ensure design depths for incorporation Needed adjustments to ph, organic matter, nutrients for plant growth Soil Restoration: When Am I Done? New York State Stormwater Management Design Manual At the end of the project an inspector should be able to push a 3/8 metal bar 12 inches into the soil just with body weight. Pick this guy as your inspector Ratio of Impervious Contributing Area to Soil Amendment Area (IC/SA) 2. Depth of Incorporation Ave. Compost Depth (inches) Incorporation Depth (inches): lower for B soils; higher for C/D soils Method Tiller Subsoiler Subsoiler, Excavation, Mixing In general, avoid IC/SA ratios > 1 Volume of Compost Needed C = A x D x Where: C = compost needed (cubic yards) A = area of soil amendment (square feet) D = depth of compost added (inches) Example Example ½ house = 600 square feet Compost-amended filter paths = 300 square feet each IC/SA = 1.0 Compost = 6 10 inches Incorporation = inches 45 cy needed d (based on 24 ) ½ house = 600 square feet Compostamended filter paths = 600 square feet each IC/SA = 0.5 Compost = 3 6 inches Incorporation = 8 12 inches 45 cy needed d (based on 12 ) Street Street 11

12 3. Compost Specifications: See Individual State Specs DE: Appendix 3, Post-Construction Standards & Specs D.C.: Appendix J, Stormwater Guidebook U.S. Composting Seal of Testing Assurance (STA) program: Alternative specifications Some differences in specs for other components (e.g., bulk density, organic matter) 4. Methods of Incorporation Deep Ripping/Subsoiler Spread & incorporate compost Grass/plant establishment NOTE: Some applications with deep incorporation of compost may require excavation and replacing soil/compost in lifts See DE post-constructon spec Complete Soil Restoration Multi-step process that includes: Composting. Tilling compost into soil. Removing large rocks. Applying topsoil. Vegetating the surface. Great Resource: Deep Ripping and De-compaction DEC Access at: ater_pdf/infildecom08.pdf 12

13 5/28/2014 Deep Ripping Photo Credit: Jeremy Balousek, P.E., Dane County, WI Land and Water Resources Department Perpendicular to Flow Direction Photo Credit: Jeremy Balousek, P.E., Dane County, WI Land and Water Resources Department Establish Vegetation Lime, Irrigation As Needed Photo Credit: Jeremy Balousek, P.E., Dane County, WI Land and Water Resources Department Spread Compost (small areas till in) Photo Credit: Jeremy Balousek, P.E., Dane County, WI Land and Water Resources Department Use Simple ESC Measures For Areas > 2,500 sf Photo Credit: Jeremy Balousek, P.E., Dane County, WI Land and Water Resources Department 13

14 Smaller Areas Design Adaptations Rototiller, Tiller Hand spreading compost Seed & straw Photo Credit: Richard McLaughlin, Ph.D., North Carolina State University Photo Credit: Jeremy Balousek, P.E., Dane County, WI Land and Water Resources Department Setting Adaptation Maintenance i.e., explain this to your neighbors Karst Ensure soil ph conforms to limestone setting Coastal Evaluate drainage & water table to ensure amendments do not become saturated Steep Terrain May need to terrace on slopes > 5% Cold Weather/Snow Linear/Highway Not recommended for snow storage areas Can be in open section swales, medians, road shoulders (filter strip) Photo Credit: Jeremy Balousek, P.E., Dane County, WI Land and Water Resources Department Maintenance First Year Inspect for 6 months Spot Reseeding Depending on soil test, one-time spot fertilization i in fall after first growing season Watering, as needed Maintenance -- Ongoing For residential homeowner education & awareness De-thatch every few years See also maintenance requirements for grass channels, filter strips, reforestation GENERALLY, A LOW MAINTENANCE PRACTICE! 14

15 Example From Stu Schwartz, UMBC Yorkwood Elementary School Baltimore, MD De-compaction - Deep Ripping and Amendment Yorkwood Elementary School Baltimore, MD standard topsoiling suburban subsoiling Slide Credit: Stu Schwartz, Center for Urban Environmental Research and Education, University of Maryland Baltimore County Slide Credit: Stu Schwartz, Center for Urban Environmental Research and Education, University of Maryland Baltimore Co. Yorkwood Elementary School August 2011 standard topsoiling standard topsoiling Slide Credit: Stu Schwartz, Center for Urban Environmental Research and Education, University of Maryland Baltimore County suburban subsoiling suburban subsoiling Slide Credit: Stu Schwartz, Center for Urban Environmental Research and Education, University of Maryland Baltimore County Where To Find Design Resources: Virginia Laws, Regulations, Permits: Virginia Dept. of Environmental Quality, Stormwater: termanagement.aspx BMP Specifications: Virginia Stormwater BMP Clearinghouse, Non-Proprietary (Soil Amendments = Specification #4): Design Guidance for Karst, Coastal, Urban/Redevelopment: Chesapeake Stormwater Network, Technical Bulletins: /csn-technical-bulletins/ Where To Find Design Resources: West Virginia Laws, Regulations, Permits: West Virginia Dept. of Environmental Protection: sw_home.aspx BMP Specifications: West Virginia Stormwater Management & Design Guidance Manual (Soil Amendments= Appendix D): ages/stormwatermanagementdesignandguidancemanual.asp x Design Guidance for Karst, Coastal, Urban/Redevelopment: Chesapeake Stormwater Network, Technical Bulletins: 15

16 Where To Find Design Resources: D.C. Stormwater Rule: District Department of the Environment: BMP Specifications: D.C. Stormwater Management Guidebook (Soil Amendments = Appendix J): Design Guidance for Karst, Coastal, Urban/Redevelopment: Chesapeake Stormwater Network, Technical Bulletins: /csn-technical-bulletins/ Where To Find Design Resources: Delaware Laws, Regulations, Permits: Department of Natural Resources & Environmental Control: ater.aspx BMP Specifications: Sediment & Stormwater Technical Document (Soil Amendments = Specification Appendix 3): cal_document.aspx Design Guidance for Karst, Coastal, Urban/Redevelopment: Chesapeake Stormwater Network, Technical Bulletins: Where To Find Design Resources: Maryland Laws, Regulations, Permits: Department of the Environment: ManagementProgram/SedimentandStormwaterHome/Pages/ Programs/WaterPrograms/SedimentandStormwater/home/i ndex.aspx BMP Specifications: Maryland Stormwater Design Manual (Chapter 5, ESD Practices): ManagementProgram/MarylandStormwaterDesignManual/P ages/programs/waterprograms/sedimentandstormwater/sto rmwater_design/index.aspx Design Guidance for Karst, Coastal, Urban/Redevelopment: Chesapeake Stormwater Network, Technical Bulletins: Where To Find Design Resources: Pennsylvania Laws, Regulations, Permits: PA Department of Environmental Protection: ormwater_management/21377 BMP Specifications: PA Stormwater Best Management Practices Manual (Chapter 6.7.3, Soil Amendment & Restoration): est_management_practices_manual/21383 Design Guidance for Karst, Coastal, Urban/Redevelopment: Chesapeake Stormwater Network, Technical Bulletins: Where To Find Design Resources: New York Q & A Laws, Regulations, Permits: NY Department of Environmental Conservation: BMP Specifications: NY State Stormwater Management Design Manual (Chapter 5): Design Guidance for Karst, Coastal, Urban/Redevelopment: Chesapeake Stormwater Network, Technical Bulletins: /csn-technical-bulletins/ 16

17 Evaluation Please take a few moments to answer our 6 question survey to help us better serve your needs in our 2014 webcast series. / /ST We use this information to report it to assess our work, your needs and to report it to our funders for future webcasts! 17