OFFICIAL PUBLICATION OF THE INTERNATIONAL EROSION CONTROL ASSOCIATION / THIRD QUARTER 2025 / IECA.ORG / VOL 20, NO. 3 EFFECTIVE DESIGN FOR SEDIMENT BASIN, P. 14 URBAN STREAM MANAGEMENT: FIRE, ARUNDO DONAX AND GEOMORPHIC IMPACTS, P. 30 IN THIS ISSUE! UPDATES FROM IECA STANDARDS AND PRACTICES COMMITTEE: CURRENT PROJECTS, FUTURE GOALS, P. 10 CHECK OUT THE IECA NEWSCENTER AT NEWS.IECA.ORG
The International Erosion Control Association (IECA) is a nonprofit, professional organization providing education, networking and research for engineers, government, consultants, construction and related professionals, for the purpose of establishing standards of practice and expertise in the fields of erosion control, sediment control and stormwater management. Environmental Connection is the quarterly magazine—published January, April, July and October—for members of IECA. Our goal is to present industry and association news, highlight member contributions to society and promote the exchange of scientific and technical information. Each issue of Environmental Connection includes peer-reviewed articles on a wide variety of timely erosion and sediment control topics, as well as regular features that provide thought-provoking accounts of people, programs and issues in the erosion and sediment control profession. Environmental Connection welcomes the submission of articles of interest to erosion and sediment control professionals at all levels. ARTICLE SUBMISSIONS www.ieca.org/SubmitArticle COMMENTS & NEWS SUBMISSIONS education@ieca.org EDITORIAL REVIEW BOARD Wesley Donald, Ph.D., CPESC, Chair John E. Andrews, PE, CPESC DJ Brouwer, PE, CFM Julie Etra, CPESC Brian Free, CPESC, CPSWQ, CPAg David Hamilton, CPESC Peter Hanrahan, CPESC Dave Jenkins, CPESC Billur Kazaz, Ph.D. Jennifer Malavasi, MS, QSM Jett McFalls, PLA Paul Mueller, CESSWI Luci Snowden, MS PUBLICATION STAFF Joy Dickinson, Editor PUBLISHED BY Big Red M www.bigredm.com ADVERTISING SALES Ronnie Jacko 503.445.2234 ronnie@bigredm.com IECA MEMBERSHIP Individuals receive Environmental Connection as part of IECA’s member benefits. Professional membership starts at $200 USD. Call 800.220.3153 or 303.640.7554 or visit ieca.org for more information. CHANGE OF ADDRESS IECA must be notified at least 30 days in advance. Magazines deemed undeliverable due to an incorrect address will be destroyed by the post office. We cannot guarantee the supply of back issues on late renewals or late address corrections. ©2025 International Erosion Control Association. All rights reserved. The contents of this publication may not be reproduced, in whole or in part, without the prior written consent of the publisher. FOLLOW US @InternationalErosionControlAssociation @iecaglobal linkd.in/19DO1JR @iecaglobal 5 CEO'S MESSAGE Finding Community Through IECA 6 BUSINESS MATTERS Fundamentals and Creative Solutions 35 INDUSTRY PROFILE Wally Butman: A Life Defined By Mentoring, Coaching 38 CALENDAR OF EVENTS 38 AD INDEX BUSINESS 30 UNIVERSITY PARTNER Urban Stream Management: Fire, Arundo Donax and Geomorphic Impacts STORMWATER MANAGEMENT 10 SEDIMENT CAPTURE New standards from IECA Standards and Practices Committee 14 EROSION CONTROL Effective Sediment Basin Design 18 CALL FOR INNOVATION Filter Sock Technology 21 INTERNATIONAL Hydroseeding at Maya Train Project 26 INTERNATIONAL Mount Messenger — Te Ara o Te Ata: A Legacy Project EROSION & SEDIMENT CONTROL 8 RESEARCH BRIEFS Wetlands to Remediate Agricultural Drainage 33 CALL FOR INNOVATION Green Infrastructure Innovation Captures up to 98% of Sediment in Coastal Erosion WETLANDS, STREAMBANKS & SHORELINE TABLE OF CONTENTS ON THE COVER: A sediment basin with porous baffles and a skimmer is shown on a roadway construction project. New standards from the IECA Standards and Practices Committee include updated specifications on basin size, geometry and detention times to maximize sediment-capture efficiency. For more information on the new standards, see the article on page 10. CORNERSTONE MEMBERS
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ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG 5 What’s in a Name? critical information and experiences with all participants. And what is the takeaway? A new generation of knowledgeable individuals or possibly the beginning of new and better procedures being developed. Over the next six months, there will be numerous online courses presented by IECA members to highlight new procedures and products. There will also be courses with valuable information to assist in wildfire recovery from urban and forest fires, as well as information surrounding flooding disasters. At the time of this article, six IECA chapters have upcoming regional conferences scheduled. Their agenda and schedule can be found on the IECA web page at ieca.org. If you are a member of one of these chapters, I hope you will spread the news. There are a number of erosion control and stormwater professionals in your sphere of influence who may not be aware of the opportunity that awaits them at these events. The IECA is not just an erosion control and stormwater association. It is a family of concerned professionals who give of their time and energy to help one another and even competitors. The game associated with the name “IECA” is to prepare each member with the tools for success, be it in their careers or community or in reaching out to help individuals in distress. Let’s keep our association’s name associated with being there for each other professionally and personally. Jerry B. Sanders, CPESC IECA President CEO’S MESSAGE I read about an interesting social experiment. It concerned the observation of two sets of groups playing the same game. The first group was told it was a community game. The second group was told the game was a Wall Street game. Although both groups were playing the exact same game, the way it unfolded was strikingly different. When the game was considered a community engagement, participants cooperated and helped each other along. In the one labeled a Wall Street game, they competed aggressively against each other. The name of the game affected the way it was played. When I think about the IECA, I see a group of professionals from a number of different backgrounds, all playing a game of saving and protecting our natural resources. A group of individuals involved in a wide variety of industries and skill sets coming together to share their experiences and their learned knowledge with one another. Individuals from around the world are striving to create a place where others can come and obtain helpful information. Information to further their individual careers, yes. But it’s more so to further the understanding and share the knowledge, procedures and products that are available for each of us to use and implement in our specific area. Earlier this year, the Southeast chapters and the IECA, with affiliated organizations, provided a variety of field days and educational conferences. The field days gave on-site demonstrations of erosion control products and structures, along with implementation procedures. The educational conferences were filled with experts who volunteered to share Jerry Sanders, CPESC IECA President “Let’s keep our association’s name associated with being there for each other professionally and personally.”
6 ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG Focusing on the Fundamentals Creating a Unique Value Proposition When it comes to business, there are fundamentals that every industry — ours is no exception — needs to follow. And much like nature, there needs to be a balance. There should be an equilibrium of standard operating procedures combined with a process of identifying creative solutions that will carve out a unique space in your market. Your unique value proposition is your company’s DNA that makes you truly different from everyone else. It explains the distinct value your product or service delivers compared to your competition while clearly underscoring why customers should buy you over anyone else. Success comes to those who balance and leverage the fundamentals with creative business models, processes, products and services not previously seen or executed in our industry. Sure, it’s easier said than done. It starts with knowing the fundamentals of business: strategy, execution, people and cash. No matter what industry or company you work in, you need these foundational blocks to grow and thrive. Judith M. Guido Chairwoman / Founder, Guido & Assoc. The essence of strategy is all about being unique by finding that white space in your industry or market that others have not. How you find that unique space is by identifying the major bottlenecks, constraints and chokepoints that others have chosen to ignore or could not figure out how to solve. They stayed the course in their comfort zone (the most dangerous place to be). Identifying industry constraints is the ultimate key to unlocking industry strangleholds. It solves those problems that eat away at customers and your team and satisfies their needs while identifying opportunities. After you have uncovered this unique space, you work collaboratively with your key market channels, including your customers, supply chain, partners, professional associations, media and competitors. That collaboration lets you communicate your strategy (your unique solution) simply to the market. Execution is all about those high-payoff processes and activities that need to be accomplished to move the company forward. It is the playbook for making the strategy come to life. It’s the “how” you do it. Consider the previous mantra of one of the greatest companies in the world, Apple. Its strategy, which still underlies its business model, was “think different.” Its execution was “do different things, and do things differently,” which is still relevant. People are best summed up by the brilliant thought leader Jim Collins, who said the essence of having a talented team is having the right people in the right seats, doing the right things, right! And those people aren’t just your immediate team. They include your supply chain, partners, customers, media and professional networks. It’s about developing leaders and people at every level and aligning them with your vision and strategy. It is creating a career path that brings out the best in them. It BUSINESS MATTERS is teaching them how to think and act creatively. Giving them the tools and a safe place to communicate and test their ideas. And finally, cash, also known as the oxygen of business. Do your strategy, execution and people provide a consistent source of cash to fuel your growth? Are you taking cash (oxygen) in at a rate and expending it at a rate that allows your company to live a long and healthy life? While cash is a four-letter word, it’s a good four-letter word. You need to create a cash culture, regardless of your role, where everyone knows how their actions affect the cash in the organization. Like oxygen, if you’re without it, you will cease to survive. By balancing the fundamentals with creativity and innovation, you’ll create a unique space that will make your competitors envious. Your team and stakeholders will be proud. About the Expert • Judith M. Guido is the chairwoman and founder of Guido & Associates, a business management consulting firm in the erosion control and green industry. Guido can be reached at 818.800.0135 or judy@ guidoassoc.com. “No matter what industry or company you work in, you need these foundational blocks to grow and thrive.”
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8 ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG Rich McLaughlin, Ph.D. Professor Emeritus North Carolina State University, Raleigh, NC Wetlands to Remediate Agricultural Drainage Reducing Nutrient Discharges to Minimize Impacts to Waterways Agricultural production often results in discharges of water heavily laden with nutrients, which results in negative impacts on receiving waters including algal blooms and eutrophication. Several types of constructed wetlands were tested recently to determine their potential for treating these waters to remove nutrients before discharge. Modeling Constructed Wetlands Researchers in one study tested different substrates in model constructed wetlands to determine which would best remove nitrogen (N), phosphorus (P) and chemical oxygen demand (COD) from simulated farm runoff.1 The model systems were contained in 16 cm diameter by 45 cm tall (6.3 x 17.7 inch) plastic pipes. The control treatment had 20 cm (7.9 inches) of 3 to 5 mm (0.12 to 0.2 inch) gravel, while two other treatments included 10 cm (3.9 inch) gravel plus 10 cm (3.9 inch) iron-carbon composites (FeC) or 10 cm (3.9 inch) iron-carbon composites mixed with ground walnut shells (WFeC). In addition, another treatment was the same as WFeC but included inoculation with a denitrifying phosphate-accumulating bacteria (MWFeC). All of the columns were inoculated with activated sewage sludge, planted with four Iris tectorum plants, and allowed to equilibrate for a month before dosing. There were three dosing periods of 40 days each, with simulated runoff being added daily to the top while removing an equivalent volume from the bottom. The pollutant concentrations during the first period were 6.0 mg NO3 -N L-1, 3.0 mg NH4+-N L-1, 0.4 mg total phosphorus L-1 (TP) and 15.0 mg COD L-1 in the form of sucrose and fulvic acids. In the second phase, the concentrations were doubled, and in the third phase, the concentrations were doubled again. The removal of NO3 increased substantially (>2X) in all treatments relative to the gravel control, with the WFeC and MWFeC treatments achieving up to 88% and 94% removal, respectively. Increasing the NO3 concentration decreased removal rates, but the MWFeC treatment still removed 77%. Removal of NH4 hovered around 60%–70% regardless of the substrate or the concentration. Total N removal followed the NO3 pattern for the treatment effects and peaked at around 75% for the MWFeC treatment at the highest concentration. Removal of TP was in the 30%–40% range for the gravel alone and about twice that for the other substrates. Similar to the nutrients evaluated, COD removal was increased with the FeC substrate and was the greatest in the MWFeC treatment at up to 90%. Iron concentrations remained low (<0.2 mg L-1) in the effluent. The authors also measured several greenhouse gases (CO2, CH4, N2O) to determine the potential for the different substrates to negatively impact global warming initiatives. The results were much more mixed than those of the column water. At the lower nutrient concentrations, generally fewer greenhouse gas emissions came from the FeC columns compared to the gravel alone. However, at the highest nutrient concentration, emissions were about 2X when the FeC material was used in the columns. Removing Nutrients with Cattail In a second study, aquaculture waste water (WW) was collected from a trout production facility and added to 2.5 m (8.2 feet) diameter stock tanks consisting of 15 cattail plants planted into 20 cm (7.9 inch) topsoil and flooded to a 30 cm (11.8 inch) depth.2 The system was allowed to establish itself for 40 days before adding the WW. Then the WW was added weekly at five doses over five weeks. The total N and P loading over RESEARCH BRIEFS
ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG 9 the entire period was 14, 35, 77, 131 and 209, and 3.0, 7.6, 17, 29 and 46 mg m2 (10.7 feet2) respectively. Weekly grab samples were obtained 1 to 2 days before dosing and analyzed for TP, total dissolved phosphorus (TDP), soluble reactive phosphorus (SRP), total dissolved nitrogen (TDN), total ammonia N (TAN), nitrite N (NO2-N), and nitrate N (NO3-N). Cattail height was measured weekly, and plant samples were taken after approximately three and seven weeks after the first WW dosing. There were tanks with cattails that received no WW and served as the controls. There was no pattern of response in the growth of the cattails related to the dosing, possibly because the cattail plants had undergone rapid growth in the period before dosing was initiated. The authors suggested there may have been a measurable response in the tubers, but these were not sampled. The system appears to readily absorb the added N, although some NO3-N spikes were detected, possibly coming from the soil. The P added to the cattail systems resulted in higher P in the water column initially, directly related to dose, but even at the highest dosing, the total P in the water column was <0.05 mg L1 at the end of the dosing. The 96% reduction in P concentrations occurred in spite of the relative lack of growth of the cattail plants during the dosing period. The authors suggest that this finding indicates that this type of constructed wetland can remediate WW even after the main growth period for the plants. (An example of fish production in aquaculture tanks is shown in Figure 1.) References 1. Cun D, Wang H, Jiang M, et. al. 2024. Effective Remediation of Agricultural Drainage at Three Influent Strengths by Bioaugmented Constructed Wetlands Filled with Mixture of Iron Carbon and Organic Solid Substrates: Performance and Mechanisms. Science of the Total Environment 947. doi.org/10.1016/j. scitotenv.2024.174615. 2. Blandford NC, McCorquodale-Bauer K, Grosshans R, et. al. 2024. Removal of Nutrients from Aquaculture Wastewater Using Cattail (Typha Spp.) Constructed Wetlands. J Environ Qual. 2024; 53:767-775. Doi: 10.1002/jeq2.20608. About the Expert • Rich McLaughlin, Ph.D., received a B.S. in natural resource management at Virginia Tech and studied soils and soil chemistry at Purdue University for his master’s degree and doctoral degree. He has retired after 30 years as a professor and extension specialist in the Crop and Soil Sciences Department at North Carolina State University, specializing in erosion, sediment and turbidity control. He remains involved with the Department as professor emeritus. Figure 1. Fish production in aquaculture tanks. RESEARCH BRIEFS
10 ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG By Christina N. Kranz, Ph.D. COVER STORY Updates from IECA Standards and Practices Committee Current Projects, Future Goals The International Erosion Control Association (IECA) Standards and Practices Committee has been creating new standards for the erosion control industry. The Committee works to develop, refine and disseminate best management practices (BMPs) for mitigating environmental impacts from construction. These standards serve as a foundation for professionals tasked with balancing the demands of infrastructure development with the duty to comply with environmental regulations. The Committee uses modeling and research to guide the way erosion control is approached to ensure standards follow BMPs. The standards are comprehensive and address everything from technical specifications to inspection and maintenance, and they aim to empower stakeholders across the industry to adopt solutions that are practical and sustainable. This commitment has made the Committee a resource in the field of erosion and sediment control. For more information about the Committee, go to ieca.org/sp. Progress and Development 1. Erosion and Sediment Control Terminology Standardization To streamline communication across the industry, the Committee has developed a comprehensive glossary of erosion and sediment-control terminology. Key terms include: • BMPs – Defined as a collection of measures to effectively mitigate erosion and manage sedimentation. Cover. Sediment basin with porous baffles and a skimmer on a roadway construction project. SEDIMENT CAPTURE PEER REVIEW • Forebay – Described as an impoundment intended to slow down water and facilitate sedimentation when placed upstream of detentionbased practices. • Hydraulic Growth Medium – Clarified by hydraulically applied media that promote vegetation when topsoil is absent or deficient. It is a useful resource, especially for those newer to the erosion and sediment control industry, to look up terms that are not familiar. This glossary standardizes language, which promotes consistency and understanding among professionals. 2. Temporary Sediment Basin Standard Temporary sediment basins are essential for capturing sediment-laden runoff on construction sites before water discharge. The new standard introduces: • Optimal Design – Updated specifications on basin size, geometry and detention times to maximize sediment-capture
ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG 11 efficiency. Best practices include incorporating multiple porous baffles to dissipate energy and enhance sedimentation (Cover photo). • Innovative Dewatering Techniques – The inclusion of surface skimmers ensures sediment remains undisturbed while water is discharged. This improves the efficiency of sediment basins. • Maintenance Guidance – Regular inspection and sediment removal protocols prolong basin lifespans. A design guide is included with the standard to demonstrate how to size the temporary sediment basin based on runoff quantity from the design storm. This detailed guide gives practitioners the tools they need to design temporary sediment basins. 3. Construction Exit Pad Standard Construction exit pads are designed to minimize soil track-out and debris from construction vehicles (Figure 1). Recent updates to the standard emphasize material specifications and improved design to accommodate varying site conditions. For example: • Length and Width – The Committee highlighted the need for customization based on site-specific vehicle traffic and soil conditions. Exit pads should be designed to accommodate narrow and wide access points, which ensures flexibility for different projects. • Geotextile Underlays – To improve durability, the standards recommend integration of nonwoven geotextile underlays beneath aggregate pads. • Traffic Control Features – Updated guidance includes measures such as flaring exit pad ends and the incorporation of a turning radius for safe vehicle movement while minimizing soil disturbance. These enhancements aim to extend the lifespan of construction exit pads and improve their efficiency, particularly in high-traffic construction sites. >> SEDIMENT CAPTURE PEER REVIEW 4. Sediment Filter Bag Standard Sediment filter bags are a critical component of dewatering systems, as they filter stormwater runoff and capture coarse particles. Recent advancements focus on: • Material Resilience – Nonwoven geotextiles are now standard due to their improved filter capacity and durability. The Committee also recommends materials resistant to ultraviolet (UV) rays to withstand prolonged exposure. • Strategic Placement – Emphasizing level ground installation promotes good functionality and minimizes risks of water bypass. Also, anchoring methods like stakes or sandbags enhance stability. • Inspection Protocols – Guidelines recommend frequent inspection and timely replacement of sediment filter bags to prevent clogging and maintain efficacy. These updates improve the reliability of sediment filter bags across various site conditions. Ongoing Initiatives As the Committee continues its mission, the focus has expanded to developing standards for floating turbidity curtains and hydromulch applications. These standards are expected to be completed in 2025. 1. Floating Turbidity Curtain Standard Floating turbidity curtains are used for controlling sediment in aquatic environments. These curtains are designed to isolate sediment-laden water, which allows particles to settle in an enclosed area. The Committee’s upcoming standard will address key aspects: • Design and Materials – Curtains are crafted from durable geotextile fabrics reinforced with ballast chains and flotation units. The Figure 1. Construction Exit Pad.
12 ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG standard will emphasize materials capable of withstanding UV exposure and hydraulic forces. • Effective Placement – Guidelines will consider different configurations, such as U shape, to isolate areas without obstructing the full channel width and account for flow velocity and tidal variations. 2. Hydromulch Standard Hydromulching, a practice involving the application of a slurry of water, mulch and seed, is a key method for stabilizing soil and promoting vegetation growth. Planned standards will provide: • Composition Recommendations – Guidance on selecting appropriate mulch types and additives based on climate and soil conditions. • Application Techniques – Best practices for even distribution and adherence to soil. >> SEDIMENT CAPTURE PEER REVIEW • Rates – Adjusting rates based on the site-specific conditions such as percent slope, slope length, soil type, aspect and expected longevity. Closing Thoughts The Committee remains dedicated to advancing erosion and sediment control measures. The Committee is working to ensure professionals have access to design standards made with current BMPs. The Committee’s efforts are making a lasting difference in the industry by developing design standards that can be used in a multitude of environments. As the Committee continues to develop and refine its standards, the Committee members hope more professionals will incorporate IECA design standards into their projects. For more information about the Committee, check out the website at ieca.org/sp. There, you’ll find all the standards and the glossary (Figure 2). About the Expert • Christina N. Kranz, Ph.D., is a Lecturer and Research Associate at North Carolina State University. Figure 2. IECA Standards and Practices Committee Standards and Glossary.
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14 ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG Figure 1. An inflow channel stabilized with geotextile liner and rip-rap. By Matthew Love Effective Design For Sediment Basin Has Four Parts Sediment basins are temporary sediment and erosion control measures designed to capture stormwater runoff on construction sites before off-site discharge. The primary function of these basins is to provide storage volume and time to promote the gravitational settling of soil particles suspended in stormwater runoff. Once these particles fall out of suspension and accumulate on the bottom of the basin, the remaining clarified water can be safely discharged off-site. These enhancements aim to extend the lifespan of construction exit pads and improve their efficiency, particularly in high-traffic construction sites. A well-designed sediment basin consists of four main parts: an inflow channel, a settling pond with porous baffles, a dewatering device and an auxiliary spillway. Part One: Inflow Channel The inflow channel is a channel that collects stormwater and conveys water in a controlled fashion to the inlet of the basin. Temporary or permanent stabilization is important throughout the length of the inflow channel to prevent erosion. Protecting the channel with vegetation, geotextile liners or riprap in place will prevent the channel itself from becoming a source of sediment (Figure 1). Installing ditch checks along the inflow channel allows for initial dissipation and collection of sediment. Capturing rapidly settling soil particles before they enter the basin provides more room in the basin for the EROSION CONTROL PEER REVIEW
ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG 15 finer sediment particles to settle. This initial treatment facilitates access for maintenance, which allows sediment to be removed more frequently without the use of heavy machinery. Part Two: Basin (Settling Pond) The preferred shape of a sediment basin is rectangular; however, depending on site conditions and topographic restraints, different shapes may be employed. Designing a basin with a length-to-width ratio of 2:1 or greater will create a longer flow path from the inflow to the outflow of the basin, which gives more time for settling to occur before off-site discharge. As with the inflow channel, stabilization of the inlet and the side slopes will prevent increasing turbidity levels from erosion occurring in the basin. The volume of the basin is split into different zones. At the bottom of the basin is a standing pool, a permanent volume of water designed not to dewater but only to infiltrate or evaporate. This pool serves to detain the water with the highest concentration of sediment for an extended period, which allows for additional sedimentation to occur. This process also serves to slow water as it enters the basin, which reduces turbulence and the risk of resuspension of already-accumulated sediment in the basin. Above the standing pool is the stormwater storage, which is the volume of the basin designed to be dewatered by the primary dewatering device. This volume should be 3600 feet3 (102 m3) per acre of the total drainage area of the site or designed to handle a two-year 24-hour storm, and it extends from the elevation of the primary outlet to the bottom of auxiliary spillway. At the top of the basin is additional storage designed to discharge over the auxiliary spillway when flow rates and/or flow volume are beyond the capacity of the primary dewatering device. This storage should be designed to handle a 10-year 24-hour storm peak flow rate. Lastly, designing some freeboard above the auxiliary spillway volume allows for water to be contained within the basin and not overflow during heavy storms. >> EROSION CONTROL PEER REVIEW Figure 2. A series of three porous baffles configured perpendicularly to flow from the inlet to the outlet.
16 ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG Promote Sedimentation: Porous Baffle Typical flow in a basin without baffles would see high-speed runoff enter the basin and move at a high velocity down the middle of the basin toward the outlet, which increases overall turbulence while ignoring using the sides of the basin for sediment settling. Porous baffles serve to improve the efficiency of sediment basins by spreading flow across the entire width of the sediment basin and slowing flow velocity to facilitate gravitational settling. Initial flow into the basin will generally be turbulent, and when there is turbulence, there inhibits the ability of sediment to settle to the bottom of the basin easily. Water that makes its way through a porous baffle will see its turbulent flow converted to laminar flow, and with laminar flow comes smooth sheets of water flowing on top of each other with little to no turbulence, creating conditions ideal for settling to occur. >> A minimum of three porous baffles should be installed perpendicularly to the flow of water between the inlet and the outlet to ensure the entire surface area of the basin is used for settling (Figure 2). One effective material for baffles is coir fiber matting sized between 700 to 900g/m2 (21 to 27 oz/yard3). Baffles should be installed so they are fully extended into the side slopes and the bottom of the basin and at a height that matches the depth of the flow over the auxiliary spillway. Flow should not be allowed under, over or around the baffles. Part Three: Primary Dewatering Outlet In a basin, as water settles to the bottom of the pond, the water at the surface will always have the lowest concentration of sediment. Therefore, basins must be dewatered from the top of the water column. The preferred method to accomplish dewatering from the surface is with a surface skimmer. Skimmers float on the surface of the water. They rely on gravity to remove water from the surface and make it flow through their plumbing and eventually through the outlet of the basin. The skimmer rises and falls as the basin fills and drains. The size of the orifice of the skimmer controls the rate at which the basin is dewatered. The design dewatering time of a basin is two to six days. Dividing the stormwater storage of the basin by this dewatering time will determine the necessary flow rate for the skimmer. It is important to list the manufacturer of the skimmer used as the basis for design on project plans. This ensures that the skimmer with the appropriate flow rate is installed in the basin. Skimmers should be installed near the outlet of the basin to allow for maximum flow time for water from inflow to outflow (Figure 3). Giving the skimmer something to rest on, like a bed of riprap or a dewatering pad, will keep the skimmer from getting mired in sediment when it is at the bottom of the basin. EROSION CONTROL PEER REVIEW
ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG 17 Figure 3. A skimmer resting in a standing pool near the outlet of the basin. EROSION CONTROL PEER REVIEW Part Four: Auxiliary Spillway Auxiliary spillways are put in place to allow excess water to safely bypass the basin when full, and they should be installed in every sediment basin. As with skimmers, these should be installed as far as possible from the inlet to maximize flow length. The spillway should be designed for a 10-year 24-hour storm peak flow rate. Also, as with other parts of the basin, it should be stabilized with nonerosive liner, vegetative cover, or stone to minimize erosion. About the Expert • Matthew Love is the inside sales manager at Faircloth Skimmer. He has certifications for stormwater control measure inspection and maintenance and level I erosion and sediment control in North Carolina.
18 ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG By Joe Moore, CPESC, MS4CECI, INDOT CSC Filter Sock Technology: Bridging the Gap Between Budget and Sustainability In the modern world of construction, where budgets are often tight and environmental regulations are growing more stringent, the intersection of cost-efficiency and sustainability has become a challenging but essential frontier. Every dollar spent on environmental compliance is scrutinized – not out of reluctance, but necessity. In most cases, decisions in this space are driven by engineers working to interpret regulatory requirements while balancing the economic interests of their clients. Typically, the objective is to meet the minimum regulatory requirements in the most cost-effective way possible. This practice, although common, has long dominated how the industry approaches erosion control and stormwater management. Engineers, often under pressure to deliver efficient solutions, look for products and practices that satisfy regulations without adding unnecessary cost burdens. When that balance is struck – compliance without overrun – it’s considered a win-win for the construction and engineering teams. However, the landscape is shifting. As environmental awareness grows and sustainability becomes not just a buzzword but a societal expectation, the industry is being challenged to think differently. No longer is it enough to simply meet the standard. Increasingly, stakeholders are asking: How can CALL FOR INNOVATION PEER REVIEW Figure 1. A newly installed stacked Bioworm application on the Lake Michigan, USA, shoreline. Sustainability Through Innovation This article is part of Environmental Connection’s mission to help grow the industry by promoting innovative research, products and technology that meet industry needs through more sustainable approaches. Articles in future issues will continue to provide multiple perspectives to promote ongoing efforts to protect natural resources.
ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG 19 we exceed it? How can we build in a way that protects natural resources not just today, but for the future? Sustainability, as defined by the Environmental Protection Agency,1 is about maintaining conditions under which humans and nature can exist in productive harmony. It’s about supporting present and future generations by respecting the systems that support life, especially our natural environment. And in the world of construction and infrastructure development, that often means re-evaluating materials, practices and long-standing norms. Interestingly, the stormwater and erosion control industry was ahead of its time in many ways. Long before “sustainability” became a global priority, this sector had already begun addressing one of the most pressing environmental challenges: keeping pollutants out of our waterways. Through innovations in design, improvements in best management practices and strict maintenance protocols, the industry has worked tirelessly to reduce runoff, trap sediments and protect aquatic ecosystems. Over time, this commitment to environmental protection has fueled a manufacturing industry focused on developing products that meet performance expectations while offering cost savings. From silt fences to wattles to sediment logs and filter socks, erosion control solutions have evolved significantly. Yet now, a new generation of concerns is pushing the industry even further — toward materials that not only perform and save money but that align with sustainable and ecological best practices. One of the most significant turning points came in 2020, when Melissa Starking of the Fish and Wildlife Service (FWS) and Carrie Tansy of the FWS Michigan Ecological Services Field Office presented findings on wildlifefriendly erosion control.2 Their research revealed some troubling consequences of common practices. Specifically, they found that synthetic netting used in many erosion control products was trapping wildlife, particularly migratory birds, reptiles and small mammals. Furthermore, they discovered that many of these geotextile products were breaking down into microplastics, ultimately contributing to waterway pollution, which was the very thing these products were supposed to prevent. The report outlined a spectrum of practices ranging from “not wildlifefriendly” to “wildlife-friendly” and offered recommendations for minimizing harm to ecosystems. It was a wake-up call for the industry. While progress had been made in water quality protection, new evidence showed that some widely used materials might be doing harm elsewhere. This revelation struck a chord with companies such as the author’s. They already manufactured Siltworm by using 100% recycled, biodegradable fill materials and incorporating repurposed lumber waste from construction sites. It was a low-profile, highly effective solution that had been replacing traditional silt fences in many applications. National Sales Manager Tiff Arcella at the author’s company said, “We were reducing waste, recycling on-site materials and improving sediment retention. But when we saw the USDA’s findings, we realized there was still more work to do, especially with the netting.” In two years, Bioworm kept over 30 million pounds (13.6 million kg) of wood waste from entering the landfill. Supporting calculations are four million linear feet (1.2 million linear meters) produced at a minimum of four pounds per linear foot (1.81 kg) equals 16 million average pounds annually (7.3 million kg) or 32 million pounds (14.5 million kg) of waste kept from landfills in the last two years (Figure 1). The fill material was sustainable, but the outer netting still relied on plastic-based geotextiles that posed risks of degradation and wildlife entanglement. The mission was clear: Redesign the product to be as sustainable on the outside as it was on the inside, without sacrificing performance or blowing up costs. CALL FOR INNOVATION PEER REVIEW >> Figure 2. Natural degradation takes place with netting material.
20 ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG CALL FOR INNOVATION PEER REVIEW >> That challenge was complex, according to President Mike Lorenzo at the author’s company. “There’s a fine line between a truly engineered solution and a commoditized product,” Lorenzo explained. “We needed something durable enough to survive a construction cycle, cost-effective enough for our clients and sustainable enough to avoid contributing to the microplastics problem. That’s not an easy equation to solve.” After extensive development and testing, the company introduced BioWorm, a newgeneration filter sock using netting made from certified fibers and textiles that are proprietary. These materials were designed to safely decompose, without releasing harmful particles into the environment. Third-party testing simulated diverse conditions, including landfills, wastewater treatment facilities, stormwater systems and natural soils, to confirm its performance and environmental safety. BioWorm achieved a 95.7% sediment retention rate during ASTM D5141 bench-scale testing, as verified by TRI Environmental, a third-party laboratory. Large-scale ASTM D7351 testing revealed 85% soil retention and 91.9% seepage effectiveness. Operationally, BioWorm offers additional advantages. Because of its ability to break down (Figure 2) while drastically reducing microplastic introduction, it can often be left in place after a project concludes, which reduces the need for costly removal and disposal. “That alone can be a game-changer for constructors,” Lorenzo said. “Removal is a huge expense, and if we can eliminate that step while improving performance and protecting the environment, everybody wins.” Michele Meyer, senior stormwater specialist with Resolution Group, recently applied BioWorm to a test site on the Interstate Highway 69 expansion outside of Indianapolis (Figure 3). Meyer has used BioWorm for slope stabilization, streambank stabilization and perimeter protection on large, fast-moving jobs and federal infrastructure projects. She reported instant and long-term options for trouble areas. “Saves time and money, and there is no need to replace or remove,” Meyer said. Data from the stormwater pollution prevention plan installation and services company indicates that removal costs can often be up to 30% of the installation costs of perimeter controls. This percentage means that if a contractor spent 10% more on the sustainable product, they would save approximately 20% on overall project line-item costs. But innovation doesn’t stop with product development. The company is working with regulators and engineers to shift the way projects are specified. Instead of writing generic specs that lead to the lowest-cost product winning by default, they’re advocating for engineered solutions to be written into project documents — solutions that factor in long-term environmental impact, not just upfront cost. “This is where real change happens,” said Lorenzo. “If we want better outcomes, we have to start upstream, with better design and specification. Our industry is capable of incredible innovation. We just need the right framework to support it.” BioWorm has demonstrated what’s possible when manufacturers, engineers and regulators collaborate to meet the challenges of our time. It’s a product born from necessity, refined through science and guided by a vision of a more sustainable future. Sustainability and affordability do not have to be mutually exclusive. In the ongoing journey to build a cleaner, more responsible world, BioWorm is helping to lead the way sustainably and cost-effectively. References 1. Environmental Protection Agency. Learn About Sustainability. epa.gov/sustainability/learn-aboutsustainability. 2. Starking M. 2021. Wildlife-Friendly Erosion Control. Fish and Wildlife Service. bit.ly/3GXnRP1. About the Expert • Joe Moore, CPESC, MS4CECI, INDOT CSC, is the founder and chief brand ambassador of Erosion & Construction Solutions. Moore has over 20 years of experience with erosion and sediment control. Figure 3. A tiered or stacked installation on a construction site on the shoreline of Lake Michigan, USA.
ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG 21 By Moisés A. Cavero; Miguel Tapia-Mendoza; Víctor Lazcano Cornejo; Juan M. Vázquez Donnadieu; Carlos F. Garcia Hydroseeding at Maya Train Project – An Environmental Challenge Hydroseeding was carried out in specific sections of the new “Tren Maya” railway that traverses the Yucatán peninsula in Mexico (Figure 1). The hydroseeding successfully revegetated embankment slopes to form a vegetative cover that mitigates raindrop impact and prevents erosion processes. The railway extends for 932 miles (1,500 km) along the Yucatán Peninsula and was divided into seven sections (Figure 2). This train crosses five southeastern Mexican states of Campeche, Yucatán, Quintana Roo, Tabasco and Chiapas. The hydroseeding was conducted between December 2023 and January 2025. The main challenges for revegetation were the type of soil, which consists of crushed limestone rock, the absence of topsoil in most of the areas and high temperatures, especially from March to June (Figure 1). A mixture of tropical grass seeds was used, specifically annual ryegrass (Lolium multiflorum) and braquiaria (Brachiaria brizantha), which were sourced from certified suppliers. Calcareous soils with high gravel content present challenges for successful revegetation. They are structurally loose and have lowmoisture retention capacity, high porosity and irregular surfaces that reduce the adhesion of applied materials. A technically efficient solution is combined paper mulch and wood fiber. Cellulose, with its fine texture, ensures more uniform coverage across the soil surface and provides high water retention. Its carbon-to-nitrogen (C:N) ratio, closest to natural source, allows good microbial activity that supports seed germination. Wood fiber contributes to the longevity of the interlocking structure that anchors effectively between coarse particles, with the amount of tackifier enhancing slope stability and erosion protection. This combination offsets the physical limitations of the substrate by integrating the absorbent properties of cellulose with the structural threedimensional wood fiber. The blend improves the efficiency of fertilizer and mycorrhizal incorporation and enhances hydraulic performance during application. To determine Figure 1. Hydroseeding while Maya train transit is on top of the fill slope. INTERNATIONAL PEER REVIEW >>
22 ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG Figure 2. The seven sections of the Maya train. the most appropriate products, the technical specifications of the main commercial brands available in the market and the Biobased certificate were reviewed to comply with the project requirements. It was concluded that the products that best met the technical requirements were High Density HMI for the cellulose component and Rainier Premium and Fiber Plus for the wood fiber component. For the construction phase of the railway, the Mexican government divided the project into seven sections, which were awarded to major local and international construction companies. These companies contracted with Mexican contractors specialized in hydroseeding. Two Mexican companies were responsible for the hydroseeding application across multiple sections of the railway. This article focuses on the work performed by one of these companies, Corporativo Mayra, which was involved in the final phase of the Tren Maya’s construction. This company was responsible for hydroseeding four sections covering 313 miles (505 km), with a total area of approximately 300 acres (125 ha). The project area is characterized by a tropical climate throughout the year, with high temperatures and a pronounced rainy season lasting half the year. The following sections provide data on average rainfall and temperature for Campeche, Quintana Roo and Yucatán, where most of the railway is located. There is a substantial difference between the dry season (December to May) and the rainy season, which begins in mid-June and extends until November (Figure 3). Temperature variations throughout the year are relatively small. The annual average temperature ranges for the three states go from 75.38 F to 90.26 F (24.1 C to 32.3 C) (Figure 4). Many different hydroseeders were used to meet needs of the project. The amount of hydroseeding materials per acre applied to embankment slopes is detailed in Figure 5. The terrain configuration along the railway varies, with embankments featuring 45-degree slopes of varying lengths and heights (Figure 6). Additionally, there are a few sections with 90-degree rocky slopes covered with three- >> dimensional mesh to be revegetated (Figure 7). Certain underpasses feature structures resembling gabion walls, locally known as “Tai walls,” which also required hydroseeding. During the hydroseeding application, logistical challenges arose, primarily regarding water availability, which was managed by the construction companies involved in the project. The hydroseeding sections lacked nearby surface water sources, such as rivers, small creeks or lakes, and water access points were limited and often distant. Moreover, water tankers were also in demand for construction activities at the same time. To address this issue, coordination was established with contractors to ensure the necessary daily water supply and, in some cases, implement a night shift to apply hydroseeding (Figure 8). The selected grass seeds were tropical, noninvasive, non-aggressive, certified and commercially available. Annual ryegrass exhibits rapid germination of six to nine days and provides quick surface coverage due to its fast growth. Braquiaria, on the other hand, germinates within 10 to 12 days and grows more slowly until it develops additional leaves. Once annual ryegrass completes its life cycle in 10 to 12 months, it decomposes, enriching the soil with organic matter. Monitoring visits were conducted to assess germination rates. Initial evaluations indicated lower-than-expected germination due to high temperatures causing excessive evapotranspiration, leading to rapid soil drying. Post-seeding irrigation was managed by the construction contractors. During evaluations, findings were shared with them to improve irrigation practices. The absence of significant rainfall in the early months further complicated the situation and prompted recommendations for early morning INTERNATIONAL PEER REVIEW
ENVIRONMENTAL CONNECTION / THIRD QUARTER 2025 / IECA.ORG 23 germination rates, both in previously seeded areas with lower initial germination and in newly hydroseeded zones. In areas with low germination, agreements were made with clients to reapply hydroseeding to ensure uniform vegetation coverage. or evening watering to retain soil moisture longer. In some cases, nighttime hydroseeding was carried out using equipment mounted on a railway platform. Frequent rainfall from mid-June through late September significantly improved Figure 3. Average rainfall registered in 2024 for Campeche, Quintana Roo and Yucatán states. Graphic credit: Servicio Meteorológico Nacional Mexico, 2024. When the rainy season began, the tackifier in the hydroseeding mix was increased to enhance soil adhesion. This approach successfully prevented runoff losses on embankments. In the Tulum section, coconut fiber blankets were installed after hydroseeding (Figure 9), while in the Playa del Carmen section, hydroseeding was applied over pre-installed coconut fiber mats. In rocky areas and Tai walls, a two-layer application was implemented: • The first layer consisted primarily of organic matter and tackifier. • This was followed by a second layer containing mulch, seeds, fertilizer, tackifier and polymer gel. Germination and grass growth on embankment slopes, which constitute 95% of the hydroseeded areas, were successful, given the challenging soil conditions. Additionally, the organic matter and fertilizers improved soil quality, which promoted the emergence of native plant species. Figure 10 shows a beforeand-after comparison. Steeper cut slopes with three-dimensional mesh showed lower germination due to their vertical nature and lack of permeable soil structure, which increased evapotranspiration and required more frequent irrigation. On Tai walls, germination and growth were more successful, particularly during the rainy season, although growth declined as rainfall decreased. Throughout 2025, ongoing monitoring of hydroseeded areas will be conducted to analyze vegetation succession dynamics, Figure 4. Average temperature in 2024 for Campeche, Quintana Roo and Yucatan states. Source: Servicio Meteorológico Nacional Mexico, 2024. Material Quantities Hydromulch 2,400 lb (1,088 kg) Seeds 105 lb (47.62 kg) Fertilizer 300 lb (136 kg) Gel polymer 3 lb (1.36 kg) Mycorrhiza 0.44 lb (0.200 kg) Organic matter 400 lb (181.4 kg) Figure 5. Amount of materials used in the hydroseeding mix per acre. >> INTERNATIONAL PEER REVIEW
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