Wally Butman
2025 IECA Lifetime
Achievement Award Winner
Wally Butman has a long history of being a successful coach in his work and his personal life.
Butman has worked for decades in the hydraulic erosion control industry, both in machines and materials. However, he spent the first six years of his professional career as a teacher/coach. During the summers, Butman worked with Parksite, a regional distributor of building materials. When they offered him a sales job, his first reaction was “I’d be really afraid to make the career change.” Butman initially took a leave of absence from education before seeing that the new career was a good choice for him.
From there, he moved to Conwed Fibers, a wood-fiber hydraulic mulch manufacturer, and eventually became a national sales manager. Next, Butman went to Finn Corp., which manufactures hydroseeders and mulch-blowing equipment, as executive vice president. He also served on the board of the International Association of HydroSeeding Professionals.
After 10-plus years at Finn, Butman went to work for Profile Products, which manufactures hydraulic mulches made partially from recycled materials. Profile Products has distribution outlets and major project work on six continents. Butman stayed there for more than 20 years and recently retired as vice president of international sales.
It was during his time at Profile Products that he returned to coaching and did it at his alma mater: Harper College. Butman had played basketball there, and it was his passion. As a coach, he had the opportunity to mentor underprivileged young men and discuss their next steps in life. Many of them wanted to play for Division 1 schools but lacked the capacity. Butman encouraged them to focus on school just in case those dreams didn’t materialize. “It was very fulfilling,” he said.
Butman carried that mentoring mindset into his professional life. He loved giving guidance to young professionals and being a strong advocate for them as they moved along in their careers. Butman advised members of the sales staff to go beyond offering just a product and a price. He told them to show empathy for the customer and explain how they could benefit them. For example, Butman encouraged sales staff to take projects to customers that increased their bottom line or showed them a better way to use equipment and materials and be successful. “It’s the difference between someone who has a product to sell and someone who brings value,” he said, “and it leads to long-term relationships.”
Butman encouraged young people to work hard on those business relationships, as well as personal ones, and to follow their dreams. “Those people who help others succeed end up being successful themselves,” he said. Butman took that same helping mindset to his involvement at the International Erosion Control Association (IECA). Samantha A. Roe, IOM, IECA chief executive officer, said that while Butman was promoting his company, he was also elevating the importance of the erosion control industry globally. “As an industry, we need to place more focus on this,” she said.
Butman believes it’s important to educate and help the industry, especially those who are starting their efforts. “Sediment control is so important to our world,” he said.
While Butman was developing international markets and conducting sales worldwide, he also promoted IECA. “It’s always been a passion of mine to support the organization,” he said. Roe traveled to China with Butman. “I learned how deep his knowledge and commitment were to the industry and the impact he has had internationally,” she said. Butman worked tirelessly to share information on erosion and sediment control, and he developed key contacts in over 80 countries.
His work led to the establishment of IECA chapters internationally. “Education about erosion and sediment control makes the world a better place,” he said. His former co-workers agree and praise him for making the world a greener and healthier environment.
Butman’s efforts have played a key role internationally and led to his receiving the 2025 IECA Lifetime Achievement Award and the 2022 IECA Sustained Contributor Award. His son Adam praised his ability to intersect business leadership with passion and impact. Adam said his father devoted “35-plus years of service to an industry that is transforming, shaping and preserving our environment through innovation in horticulture, erosion control and sports turf management. His career efforts have helped shape agriscience on a global scale, preserving and maintaining millions of acres of land.”
Figure 1. Applying a topsoil alternative product on California wildfire projects.Figure 2. In-field training on hydraulic erosion control.
Such comments bring the elder Butman to tears. He is proud of his two sons, Jake and Adam, and daughter, Brittney, as well as his wife, Eileen, of 46 years, who kept the household running when Butman’s job demanded heavy travel.
Now that Butman has retired, he is looking forward to some consulting opportunities along with some Board activities. But more importantly, he will be spending more time with his family, including his six grandkids, and improving his golf game. “Now that I have more time to play, I have no excuses,” he said.
Figure 3. Butman found presenting individual awards to be very rewarding.Figure 4. Butman examines erosion control techniques near Beijing with China representative Jia Hu.
About the Expert • Joy Dickinson is the editor of Environmental Connection.
Val Barragan: IECA’s Education
And Conference Manager
The International Erosion Control Association (IECA) is welcoming Val Barragan as education and conference manager. Barragan joins the IECA with a passion for impactful program development and a strong background in event management, stakeholder engagement and educational strategy, according to Samantha A. Roe, IOM, Chief Executive Officer of the IECA.
“Based in Denver, Colorado, USA, Val brings years of experience designing and executing dynamic educational programs and conferences that drive engagement and deliver value,” Roe said. “In her new role, she will lead the planning, development and execution of IECA’s educational initiatives and events, while working closely with members, partners and industry experts to further our mission of protecting soil and water resources through high-quality education.”
Barragan has eight years of experience in scientific communication, stakeholder engagement and public health initiatives. She has a BAAS in biology and technical writing from Texas (USA) State University. She will play a key role in enhancing the reach and impact of IECA’s conferences, workshops and webinars. “Her leadership will ensure that our members continue to benefit from innovative programming and valuable networking opportunities,” Roe said.
Barragan said, “I’m thrilled to join IECA as the new education and conference manager, where I’ll blend my passion for sustainable resource management with my love for connecting people through education. With a background in science communication, I’m committed to advancing erosion control solutions and empowering our community with impactful knowledge.”
Figure 1. Soil stabilization, Prince Edward Island (PEI) (2022). Photo credit: Helping Nature Heal.
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.
The Atlantic shores on the Eastern side of North America face particular challenges due to climate change and sea-level rise. Canada is expected to warm at nearly twice the global rate, and significant storm events are happening with greater frequency and intensity. Due to land subsidence, or the sinking of the coastline due to the last glaciation, the relative sea-level change is expected to be higher than the global average in the Atlantic region, with a rise of 60 to 100 cm (24 to 40 inches) predicted.
The shorelines are particularly vulnerable to erosion. Thousands of public and private properties are already being affected along Atlantic coastal communities. Erosion rates for coastal bluffs in Nova Scotia are as high as 10 m (11 yards) per year for newly exposed headlands.1 Sea-level rise and increasing storm intensity are accelerating coastal erosion.
Coastlines are dynamic, living ecosystems that transform naturally through erosion, sediment transport and deposition. While many landowners build hard armour walls to protect individual properties from erosion, this grey infrastructure comes with high costs, ecosystem damage, biodiversity loss and limited efficacy.
Helping Nature Heal (HNH) is an ecological restoration company based in Nova Scotia, Canada. They work with nature to restore living shorelines (Figure 1). HNH was driven by the challenge of effectively addressing coastal erosion using a sustainable green infrastructure alternative to hard armour, which presents secondary effects.
This challenge has led to the development of Living Shorelines, which is a three-part method for coastal protection that has resulted in up to 98% sediment capture. Living Shorelines is a soft engineering approach to mitigate the effects of erosion on waterfront property without endangering the coastal ecosystem (Figure 2). It includes:
Application of condition-specific native plant companion groupings.
Low-tech green techniques for planting on steep and eroding slopes.
A plant nutrition product, Abundance root booster, that stimulates root growth. This 100% natural organic soil booster fosters healthier root systems, showcased through increased root diameter and length, reduces the rate of erosion to 1% to 2% of previous sediment runoff and enhances the resilience of coastal areas.
HNH designs condition-specific native plant groupings for each job, with the goal of optimizing healthy, rapid and dense root development. Factors are considered such as soil composition, incoming energy (solar, wind, water, etc.) and plant species characteristics. Each design specifies the plant species, groupings and density that will be most resilient to change, even when challenged by climate issues.
Over hundreds of projects, a series of low-tech, low-cost green techniques were developed and refined for planting on steep and eroding slopes, such as those in Prince Edward Island (Figures 1 and 3). Erosion chevrons, wattle fencing and veggie groynes are a few of the methods used to successfully establish plantings in very challenging terrain conditions. These methods add no inorganic materials to the site, which prevents pollution and allows the site to re-naturalize with minimal further intervention (Figure 3).
Abundance is an all-natural concentrate root booster that helps plants establish new roots, reduces transplant shock and plant loss, permanently improves nutrient and water uptake, and permanently improves disease resistance. It is applied in all Living Shorelines and other restoration projects and is also provided as a standalone product.
Abundance is enriched with essential nutrients and minerals from land and sea. This award-winning soil booster ensures that plants thrive naturally. It won the Kelp Fest 2024 Product Award from the Ecology Action Centre.
The formulation includes kelp iodine concentrate (typically 50 ppm/L or 50 mg/L) with over 70 minerals, vitamins, trace elements, amino acids and citric acid. The produce is specifically formulated with mycorrhizal fungi and beneficial bacteria, with total nitrogen 11%, available phosphate 0.5% and soluble potash 7%. It is 100% biodegradable.
Figure 2. Shoreline stabilization (2023). Photo credit: Helping Nature Heal.Figure 3. Living shoreline construction, Prince Edward Island (PEI) (2022). Photo credit: Helping Nature Heal.
The formula has been developed through rigorous scientific research and extensive testing. The research and innovation sector of Lambton College, Ontario, Canada, conducted a study on the tensile strength of HNH plant recipes combined with Abundance. The study concluded that “overall better results were obtained” from the use of Abundance. In particular, it was found that by month three, yellow willow plants treated with Abundance and an additional biomass layer experienced overall growth by 384.4%, compared to plants with no treatment experiencing only 16.7% growth. This significant increase underscores the impact of Abundance in promoting plant growth and stability, which is crucial for erosion control projects.
In addition to tensile strength studies, rigorous rainfall tests were conducted to further validate the effectiveness in erosion control. Three rainfall tests were conducted, with each lasting 15 minutes and conducted biweekly. The rainfall intensity was set at 100 mm/h (4 inches/hour), based on rainfall intensity-duration-frequency (IDF) curve data specific to the Sarnia, Ontario region in which the tests were conducted. The tests were performed on a slope set at 45 degrees to simulate challenging real-world conditions. Water runoff was measured, and soil runoff was collected, dried and weighed. These tests demonstrated that Abundance significantly reduced soil erosion and water runoff to 1% to 2% of the runoff measured without the use of bio-stimulant.
Reference
Natural Resources Canada, Geological Survey of Canada — Atlantic. 2007. Understanding Nova Scotia’s Coastlines, p. 2.
About the Expert
Emillie Rose is the project manager at Helping Nature Heal in Bridgewater, Nova Scotia, Canada. She has an advanced diploma in fish and wildlife technology and is certified at Level 2 by Green Shores.
Figure 1 - Top image: 8 June 2018 burned riparian and hillslope. Middle image: 29 June 2018 burned riparian and hillslope with giant reed and palm regrowth in the riparian, Bottom image: 26 April 2019 non-native vegetation dominates post-fire site.
The escalating severity of wildfire seasons in California highlights the urgent need for effective land and water resource management. Fires in urban riverine systems can threaten lives and infrastructure while severely impacting stream health and stability; specifically, post-fire flooding and sediment transport can degrade essential drinking and recreational water sources. 1,2 While immediate post-fire impacts on surface hydrology such as sedimentation and flooding are well-documented, studies in semi-arid urban systems, where human activities significantly alter natural fire and hydrological regimes, remain limited. In addition to geomorphic changes that affect erosion control, water quality and sediment dynamics, urban fires can create additional strain on limited firefighting resources. This issue is exemplified by the 2018 California wildfire season, which required the simultaneous efforts of nearly 10,000 firefighters and the significant utilization of out-of-state resources.3
To effectively address post-fire geomorphic changes in urban streams, practical research-based insights into fire and vegetation management strategies are needed to support the development of resilient urban water systems. In 2024, the number of fires was within the five-year average, but the number of acres burned was over five times the average due to increases in flammable vegetation that spread fire. 4,5 In semi-arid urban stream systems in southern California, elevated year-round water levels contribute to increased nutrient loads and more frequent flash floods. These conditions encourage the infestation of flammable invasive vegetation, which alters erosion patterns and streambank stability. 6,7
The role of fire in riparian and wetland systems is not well understood, which may be due to the presumption that these habitats serve as barriers to fire due to high moisture content of soil and vegetation. However, flammable and invasive vegetation are making urban riparian systems prone to fire.8 For example, Arundo donax (giant reed) and Washingtonia spp. (desert fan palms) significantly increase fire fuel loads in urban riparian zones.9 Washingtonia filifera is native to isolated springs in the Sonoran Desert bioregion, while Washingtonia robusta is native to Baja California. Both species have spread from ornamental plantings and are known to influence fire regimes and become fire hazards as their populations increase. Giant reed is a large, bamboo-like grass from southern Eurasia that alters the diversity and function of riparian corridors throughout coastal California. Giant reed has fueled fires around urban areas and facilitated fire spread to natural areas; it inhibits post-fire recovery and can rapidly resprout from rhizomes. The rapid post-fire growth of giant reed contributes to an invasive grass-fire feedback cycle and further alters stream geomorphology.10,11 This cycle contributes to the increasing frequency of small urban fires (under 1,236 acres or 5 km2) in southern California4 and is exacerbated by human activity (i.e., power lines and recreational areas) near stream corridors.12 Dense vegetation, such as giant reed stands, also provides shelter for unhoused individuals, which has been associated with an increase in fire incidents. For example, the Los Angeles Fire Department reported that fires related to unhoused individuals nearly tripled in three years and accounted for 54% of their total fire responses.13
Historically, giant reed was introduced for erosion control along streambanks and ditches to increase stability.14 Almost 9,000 acres (36.42 km2) from Monterey to Mexico are infested with giant reed in southern California.15 The invasive species contributes to long-term trends of channel narrowing, channel bed aggradation and floodplain accretion.16,17,18 While removal of giant reed is recommended for riparian health, anticipating acute geomorphic changes from restoration is crucial for effective stream management in urban environments.
Pre- and Post-Fire Channel and Floodplain Dynamics
Alvarado Creek is an urban and perennial stream in San Diego, California, USA. The climatology is semi-arid and Mediterranean with warm, dry summers and cool, mild winters. There is substantial non-native vegetation in the riparian zones, which is representative of many urban riparian areas in the San Diego River watershed and many urban and coastal watersheds in southern California. A reach of Alvarado Creek was burned by a brush fire (Del Cerro Fire) on 3 June 2018 due to human ignition. Fueled by overgrown and invasive and flammable vegetation (giant reeds and palms), the fire burned 37 acres (0.15 km2). Rapid regrowth of giant reed was observed one week after the fire and dominated the landscape in subsequent years. Removal of burned and non-native vegetation occurred in fall 2020, which provided an opportunity to evaluate pre- and post-fire restoration. Additional herbicide treatment was applied to eradicate remaining giant reed roots and regrowth in fall 2021.
The giant reed significantly altered urban stream geomorphology both pre- and post-fire in Alvarado Creek. Before the fire, dense giant reed stands trapped sediment, forming berms and secondary channels, with accumulation rates comparable to those observed in much larger river systems.17 Although rapid regrowth of giant reed initially provided stability to upper streambanks after the Del Cerro Fire, the absence of native vegetation cover ultimately resulted in intensified bank undercutting, channel incision and significant floodplain erosion (Figure 1).
Channel and Flood Dynamics after Vegetation Management
Following the removal of giant reed, herbicide treatment resulted in further bank undercutting, collapse and overall channel widening. These observations demonstrate the substantial geomorphic disruption caused by the removal of giant reeds in smaller, urbanized streams, with retreat bank rates comparable to those in significantly larger systems.19 This disruption highlights the dual role of giant reeds in stabilizing and destabilizing streambanks. The rapid geomorphic changes triggered by the presence of giant reed, coupled with the lack of native vegetation and its abrupt removal, underscore the need for integrated erosion control strategies that account for the complex interplay between invasive vegetation species and stream dynamics (Figure 2).
The abrupt eradication of giant reed, particularly in post-fire urban waterways, triggers complex hydraulic, geomorphic and sedimentation responses that are understudied. However, as the Alvarado Creek recovers and native vegetation regrows, the geomorphic state has started to stabilize and gradually approach similar conditions to a nearby unburned, native vegetated site. Successful removal of the giant reed and subsequent native vegetation restoration may ultimately restore the natural geomorphic processes of the stream. Manual weeding and application of herbicide treatment can be used to control non-native vegetation and allow time for native vegetation to return. Also, a plant palette that reflects the local and native populations can be used to restore the native riparian conditions. In Alvarado Creek, seeds and cuttings were collected locally to ensure the genetic makeup and diversity were reflective of the native plant populations. This consisted of native willows, cottonwood and a variety of shrubs, grasses and wildflowers. We encourage future research to prioritize high-resolution modeling and at-risk area identification to develop optimized management strategies, which will benefit the long-term health and resilience of urban riparian ecosystems.
About the Experts
• Alicia M. Kinoshita, Ph.D., is an associate professor of civil engineering and director of undergraduate research at San Diego State University. She is an expert in short- and long-term watershed and hydrologic impacts of wildfire using remote sensing and field methods.
• Danielle S. Hunt graduated from San Diego State University with a Master of Science in civil engineering and a specialty in water resources. She is a design engineer at Stevens Cresto Engineers.
Acknowledgments
The material is based upon work supported by the Joint Fire Science Graduate Research Innovation (GRIN) Award No. 31-1-01-35, San Diego River Conservancy under Grants SDRG-P1-18-1, SDRG-P1-18-15, SDRG-P68-21-03 and SDRG-B22-05 and National Science Foundation CAREER Program under Grant No. 1848577.
References
White MD, Greer KA. 2006. The Effect of Watershed Urbanization on the Stream Hydrology and Riparian Vegetation of Los Peñasquitos Creek, California. Landscape and Urban Planning, 74:125-138.
Stein ED, Brown JS, Hogue TS, et. al. 2012. Stormwater Contaminant Loading Following Southern California Wildfires. Environmental Toxicology and Chemistry, 31:2625-2638.
D’Antonio CM. 2000. Fire, Plant Invasions, and Global Changes. In: Mooney HA, Hobbs RJ (eds). Invasive Species in a Changing World. Island Press, Washington, DC, pp. 65-93.
Coffman GC. 2007. Factors Influencing Invasion of Giant Reed (Arundo Donax) in Riparian Ecosystems of Mediterranean-type Climate Regions. Doctoral dissertation, University of California, Los Angeles, CA.
Drill S. 2018. Sustainable and Fire-Safe Landscapes: Achieving Wildfire Resistance and Environmental Health in the Wildland-Urban Interface. Fremontia, 38:37-41.
Coffman GC, Ambrose RF, Rundel PW. 2010. Wildfire Promotes Dominance of Invasive Giant Reed (Arundo Donax) in Riparian Ecosystems. Biological Invasions, 12:2723-2734.
Stover JE, Keller EA, Dudley TL, et. al. 2018. Fluvial Geomorphology, Root Distribution, and Tensile Strength of the Invasive Giant Reed, Arundo Donax and Its Role on Stream Bank Stability in the Santa Clara River, Southern California. Geosciences, 8:304.
Mathews LEH, Kinoshita AM. 2020. Vegetation and Fluvial Geomorphology Dynamics After an Urban Fire. Geosciences, 10:317, doi:10.3390/geosciences10080317.
Syphard AD, Keeley JE. 2015. Location, Timing and Extent of Wildfire Vary by Cause of Ignition. International Journal of Wildland Fire, doi: 10.1071/WF14024.
Bell G. 1998. Ecology and Management of Arundo Donax and Approaches to Riparian Habitat Restoration in Southern California. In: Brock JH, Wade W, Pysek P, et. al. (eds.). Plant Invasions. Backhuys Publishers, Leiden, The Netherlands.
Giessow J, Casanova J, Leclerc R, et. al. 2011. Arundo Donax (Giant Reed): Distribution and Impact Report. State Water Resources Control Board Invasive Plant Council: California, pp.1-240.
Allred TM, Schmidt JC. 1999. Channel Narrowing by Vertical Accretion Along the Green River Near Green River, Utah. Geological Society of America Bulletin, 111(12):1757-1772.
Friedman JM, Vincent KR, Shafroth PB. 2005. Dating Floodplain Sediment Using Tree-ring Response to Burial. Earth Surface Processes and Landforms, 30:1077-1091.
Dean DJ, Schmidt JC. 2011.The Role of Feedback Mechanisms in Historic Channel Changes of the Lower Rio Grande in the Big Bend Region. Geomorphology, 126:333-349.
Pollen-Bankhead N, Simon A, Jaeger K, et. al. 2008. Destabilization of Streambanks by Removal of Invasive Species in Canyon de Chelly National Monument, Arizona. Geomorphology, 103:363-374.
Figure 2. Conceptualization of fire and invasive plant disturbances.
The Mount Messenger Alliance is delivering an essential infrastructure link in New Zealand: Te Ara o Te Ata, the Mount Messenger Bypass. The Mount Messenger section of State Highway 3 network is critical in connecting the remote Taranaki region with economic ties, tourism linkages and essential services to the northern Waikato Region. The existing section of State Highway 3 is narrow, steep and increasingly unable to safely support the vehicles and large freight trucks using it daily.
To improve resilience, reliability, safety and driving experience, a new bypass was proposed. Construction commenced in 2022. By bringing together expertise from contractors, consultants and iwi (local indigenous people), the Mount Messenger Alliance is setting a benchmark in environmental practice and actively upholding the concept of kaitiakitanga, which is guardianship and protection of the environment.
The ethos for environmental management on the project is “Ka ora te wai, ka ora te whenua, ka ora te tangata,” which means “if the water is healthy, the land will be nourished, and the people will thrive.” A holistic cultural lens is cast over all aspects of project work, from planning and design to construction and long-term maintenance. Cultural considerations are not limited to management; the name “Te Ara o Te Ata” was gifted to the project by iwi. The name translates to “the path of Te Ata,” who is the taniwha (entity or spirit) guarding the Parininihi lands where the project is located.
The deliverables of the project are not unique: 3.7 miles (6 km) of two-lane highway, two bridges, one tunnel and stream diversions; however, the environment in which the authors are working poses exceptional challenges for design and construction. The project is within a landscape of ecological and cultural significance. The area is characterised by mature podocarp forest and is home to many rare and threatened native species, including western brown kiwi (Apteryx mantelli). Toward the southern extent of the alignment is the regionally significant Mimi Wetland (Figure 1). Within this wetland are examples of the critically endangered swamp maire (Syzygium maire) and swamp forest ecosystems that include kahikatea (Dacrycarpus dacrydiodes) and pukatea (Laurelia novae-zelandiae).
The project alignment has space and access constraints, steep slip-prone slopes typically greater than 20% and highly mobile silt-based substrates. The alignment intersects the Mangapepeke Stream and Mimi River catchments, which are flashy and soft-bottomed (mud and loose sediment) with high levels of natural erosion.
The rough terrain, limited space and access to the site have driven some innovative solutions, such as the construction of a 0.7 mile (1.1 km) long cableway (Figure 2). This is the first of its kind to be used in New Zealand for the construction of a highway. The cableway provides access to the remote northern section of the project, which is otherwise only accessible by foot. With a load capacity of 44,092 pounds (20 tonnes), the cableway brings materials and machinery into the work area. Large machines must be transported in sections and built on-site. A custom eight-person gondola carries trained personnel on a 10-minute trip into the gully (Figure 3). When the gondola is not available, the alternative access route is scaffold staircases, with over 700 stairs and 656 feet (200 meters) of elevation gain (Figure 4).
defaultFigure 3. The custom eight-person gondola used to transport staff into the northern zone.
Access and space restraints have meant earthworks must begin before the installation of typical erosion and sediment controls (ESCs). In large parts of the site, these restraints have been a common problem. This situation has meant our team has developed innovative staging and designs to ensure construction could progress without adverse environmental effects.
The largest fill site on the project is known as Fill 12 and requires the filling of three main gullies to a depth of 131.2 feet (40 m), with approximately 78,4770 yard3 (600,000 m3) of material. To start this fill, a 0.43-mile (700-m) section of stream had to be diverted through 55-inch (1,400 mm) pipes. This work was completed under an online methodology that had to accommodate a one-in-100-year rainfall event (5.9 inches [151 mm] per 10 minutes).
Once a small portion of the stream diversion was completed, the fill height was increased sufficiently to allow a small sediment pond to be installed. This process repeated several times over the construction season with an additional two large sediment ponds constructed completely in fill to accommodate the dirty water catchment of the site. The period between having the ponds constructed meant all un-stabilised catchment had to be completed under a “cut-and-cover” methodology, meaning large areas of the site were covered with polythene and geotextile to eliminate sediment run-off. Since beginning these stream diversion works in 2023, we have managed to fill the area to a sufficient height to allow for a large sediment retention pond with a capacity of 12 acres (5 ha) of catchment, to be constructed at the most downstream extent of the site (Figure 5).
Figure 4. The scaffold staircase features 700 stairs and is used daily for worker access to the site.Figure 5. Temporary sediment retention pond constructed in Fill 12 with a catchment capacity of 5 ha (12.3 acres).Figure 6. The temporary outlet system of the sediment pond during construction.Figure 7. The temporary sediment pond in operation with a dispersal outlet system.
Site access and other limitations have led to the development of unconventional ESCs, which require third-party technical review before installation. One example of this unconventional ESC is a sediment pond outlet structure that sought to disperse discharge flows to prevent erosion on a 30-degree slope (Figure 6). Using a concrete manhole riser and six perforated outlet pipes, the authors were successfully able to prevent scour and erosion. The device performs as well as those with traditional outlet structures in terms of meeting discharge requirements (Figure 7). This innovative approach received the Excellence in Innovation award from the International Erosion Control Association (Australasia).
Given the ecological and cultural significance of the landscape, effective ESCs are essential. A comprehensive monitoring programme informs the construction team about the effectiveness of controls on-site. This includes baseline monitoring of water quality, ecological markers, routine monitoring of devices and controls, rainfall-based water quality, ecological monitoring, continuous in-stream nephelometric turbidity unit (NTU) monitoring and in-stream static sampling. Telemetered in-stream NTU monitors at six locations across the alignment provide real-time insight into stream conditions (Figure 8).
The Project Regulator (Taranaki Regional Council) receives automatic notifications when downstream NTU exceeds an agreed “trigger level.” This encourages open communication between the Alliance and Regulator regarding on-site activities. Additionally, we have been able to use the NTU monitors to develop a “risk-based” approach when completing in-stream works. Escalating NTU trigger alerts are sent to key staff members, and construction work will cease before the downstream agreed trigger level is reached, which eliminates sediment deposition and downstream ecological impacts.
To encourage transparency and accountability regarding water quality monitoring, upstream and downstream NTU data are made publicly available each week. Additionally, after a rain event (0.98 inches [25 mm]/24 hours or 0.59 inches [15 mm]/60 minutes), a rainfall trigger inspection report is sent to the Regulator. These reports are also made publicly available and include inlet and outlet NTU, clarity and pH results from each sediment treatment pond on site. In-stream static sampler NTU, total suspended solids and pH, and sediment deposition results in the Mimi Wetland are also made available.
Figure 8. An example of an in-stream NTU monitor.
The ESC requirements of the project are managed on-site by the ESC team lead with two senior ESC advisors. This core team works closely with two ESC supervisors and a team of skilled labourers split across the active construction zones. The ESC team collaborates closely with the ecology and engineering teams to develop construction methodologies that meet the requirements of all disciplines. The process to develop effective ESCs on-site is thoroughly planned, reviewed and implemented. A “feedback loop” process is used to allow learnings to be incorporated back into management plans to ensure continuous improvement.
Te Ara o Te Ata is using a holistic approach to environmental management. While working in a challenging environment, the Alliance has used an adaptive strategy for erosion and sediment controls. Te Ara o Te Ata will have quantifiable benefits that stretch beyond the delivery of a road. These gains include innovation and knowledge-sharing with the industry (Figure 9), social and cultural benefits, and positive ecological outcomes that will leave a lasting legacy on the Taranaki region.
About the Experts • Megan Dredge, CEnvP, is the ESC Team Lead for the Mount Messenger Bypass and is director of MPD Environmental Limited, a consulting firm in New Zealand. She has over 10 years of experience working in the ESC industry on large infrastructure projects.
• Jessica Griffiths, PGDip (Environmental Science), is a senior environmental advisor with HEB Construction, based at Te Ara o Te Ata. She is a certified environmental professional with seven years of experience across civil construction, tunnelling and mining.
• James. B Skurupey, MSc (ENVR), CEnvP, has 17 years of experience in the environmental industry, including roles as consent officer, resource management officer, environmental advisor and manager, as well as a stormwater engineer. Skurupey’s experience is across New Zealand’s local government, civil construction and mining industries.
Figure 9. IECA 2024 site field trip with industry experts in Fill 12.
Hydroseeding while Maya train transit is on top of the fill slope.
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 low-moisture 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 three-dimensional wood fiber. The blend improves the efficiency of fertilizer and mycorrhizal incorporation and enhances hydraulic performance during application. To determine 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).
Figure 2. The seven sections of the Maya train.
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 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 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.
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 before-and-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.
Figure 3. Average rainfall registered in 2024 for Campeche, Quintana Roo and Yucatán states. Graphic credit: Servicio Meteorológico Nacional Mexico, 2024.
Figure 4. Average temperature in 2024 for Campeche, Quintana Roo and Yucatan states. Source: Servicio Meteorológico Nacional Mexico, 2024.
Throughout 2025, ongoing monitoring of hydroseeded areas will be conducted to analyze vegetation succession dynamics, as native species are expected to gradually replace the planted grasses. This information will be presented in a future article.
Figure 5. Amount of materials used in the hydroseeding mix per acre.
Conclusion The hydroseeding application along the Maya Train corridor stands as a milestone in large-scale revegetation work, for Latin America especially, in geographic scope and technical execution. Carried out across approximately 300 acres (more than 125 hectares) under extremely challenging conditions — poor, rocky soils with little to no topsoil, high temperatures, a specific rainfall window and limited surface water access — this project demanded adaptive strategies and operational innovation. From selecting fast-germinating, non-invasive tropical grasses to coordinating irrigation logistics and adjusting application techniques based on slope type and seasonality, the work combined biological precision with logistical agility. The successful establishment of vegetation in such an environment not only achieved the project’s erosion control goals but also created a replicable framework for similar efforts across the region. As a reference case, it offers valuable insights for future infrastructure projects facing analogous constraints in tropical climates, degraded soils and remote locations throughout Latin America.
Figure 6. Typical fill slope along the railway.Figure 7. Cut slopes in a rocky area.Figure 8. Hydroseeder mounted on a railway platform.Figure 9. Coconut fiber blanket being installed after hydroseeding was applied.
Figure 10. Pre- and post-application comparison.
About the Experts • Moisés A. Cavero is the director for Latin America at Hamilton Manufacturing Inc. (HMI). He has more than 30 years of experience in erosion control and revegetation. He has worked on projects in Ecuador, Bolivia, Mexico, Panama and Peru.
• Miguel Tapia-Mendoza is CEO of Corporativo Mayra in Mexico. He has extensive experience with comprehensive solutions for environmental care, environmental consulting, erosion control, hydroseeding, reforestation, landscaping and nurseries.
• Víctor Lazcano Cornejo is a civil engineer and serves as operations manager of Corporativo Mayra. He has 25 years of experience in industrial gardening, landscaping, irrigation systems and manual and hydroseeding revegetation.
• Juan M. Vázquez Donnadieu is the founder of Preslam Concrete, Dovac and Vadone Construction. He is an architect and businessman. He joined Corporativo Mayra in 2023 as the administration director. He participated in the Maya train project, reforestation projects and the Pachuca-Huasca highway remodeling.
• Carlos F. Garcia is a forestry engineer specializing in environmental management in mining, energy, and oil and gas projects. Garcia has more than 30 years of experience working in bioremediation of disturbed areas. He is a pioneer in hydroseeding in Peru.
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.
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 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 wildlife-friendly 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 wildlife-friendly” 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.
Figure 2. Natural degradation takes place with netting material.
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 new generation 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.
Figure 3. A tiered or stacked installation on a construction site on the shoreline of Lake Michigan, USA.
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 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.
Figure 2. A series of three porous baffles configured perpendicularly to flow from the inlet to the outlet.
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.
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.
Figure 3. A skimmer resting in a standing pool near the outlet of the basin.
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.
Cover. Sediment basin with porous baffles and a skimmer on a roadway construction project.
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
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.
Forebay – Described as an impoundment intended to slow down water and facilitate sedimentation when placed upstream of detention based 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 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.
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.
Figure 1. Construction Exit Pad.
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.
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.
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 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.
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).
Figure 2. IECA Standards and Practices Committee Standards and Glossary.
About the Expert Christina N. Kranz, Ph.D., is a Lecturer and Research Associate at North Carolina State University.
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 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.)
Figure 1. Fish production in aquaculture tanks.
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.
