Project Proposal: “BioPro” -- Bioswale Maintenance Made Easier
Project Objective: To make the maintenance of bioswales, an environmentally friendly mechanism to filter stormwater pollutants, easier. This, in turn, would ultimately improve the overall stormwater filtration process and the environment.
Project Rationale:
Water is a critical part of our lives. We depend on it for so many things; drinking, showers, washing, and many other daily activities. Water is collected, used, and disposed in many ways. Although the disposing of water doesn’t seem like an important issue, it is. Wastewater treatment plants have many different methods of filtering and disposing of water. However, if wastewater, including storm water, is filtered closer to the source, it helps reduce the load on these expensive water treatment plants and allows them to focus on dirtiest wastewater, like sewage. This is where bioswales come in.
Bioswales use natural methods for filtering stormwater. They are Low Impact Development systems (LIDs) since they use natural features around them to protect water quality. Bioswales are shaped as a ditch, so that the water can easily flow down. They have many layers like plants, mulch, soil, gravel, and a filter sheet that filter out different pollutants. The plants filter out majority of the pollutants like nitrates and phosphates. The absorption of these phosphate rich compounds (which are very harmful to aquatic life) before they reach the streams, helps stop the eutrophication process, where excessive nutrients from the runoff causes dense growth of plant life and death of animal life in water bodies. The filtered water, eventually, is released into a stream.
Volunteers and workers from local water management facilities like Clean Water Services in Oregon, face several problems with the maintenance of bioswales. Some problems include pipe clogging, trash, weeds, stagnant water, and the replacing and watering of plants. It costs about 6 to 21 cents per square foot to maintain a bioswale. Solving the maintenance problems can provide significant cost and time savings. There is a federal requirement to have LIDs built into new neighborhoods. Every municipality needs to comply with the federal NPDES MS4 (National Pollutant Discharge Elimination System, Municipal Separate Storm Sewer System) permit requirements. These permits are issued by each state’s EPA (Environmental Protection Agency) and are typically valid for 5 years. There are specific requirements that each municipality has to meet to maintain the permit. Given this, addressing the maintenance problems can have a wide ranging positive impact across LIDs deployments nationwide.
In order to minimize the maintenance problems, my solution is to use sensors to detect maintenance problems and to create an app called “BioPro”, that can track the maintenance challenges like trash, weeds, and plant status and alert on evolving issues. The app has a log that helps track the problems, cost of repairs, and number of maintenance visits. The app will also have a dashboard that highlights key maintenance alerts, recurring issues, and summary data of bioswales. The app’s reminders can remind workers and organizations on critical maintenance activities. Some common reminders would be for trash cleanup, removing weeds, and watering the plants for the first 90 days of building a bioswale (proper watering during that time is critical for growth of plants that provide the primary filtration mechanism). Custom reminders can also be created.
I plan to incorporate three different sensors: water level sensor, water flow meter, and soil moisture sensor. The water flow meter, placed at the outgoing water pipe, helps detect the water clogging by comparing the amount of filtered water to average inches of rain on a given day. An unusually low amount of filtered water would be a potential sign of clogging. The water level sensor measures the level, twice a day, at key points on the bioswale to check if water level is staying the same or increasing. This would help detect stagnant water. Stagnant water is a problem because it attracts mosquitoes. The soil moisture sensor checks moisture once a day to check if the plants have enough water. In the summer, when rainfall is less, this can give early alerts on bioswales needing watering. These sensors will be integrated into an Arduino electronic board that can help send the data to a remote cloud server. The Arduino board will be connected to mini solar panels that will power the board and sensors. A backup battery box can provide power to augment the solar panels. Considering cost of sensors, installing, connecting, and powering them, the total cost of this setup will be around $130, plus around $14.40 per month for a public cloud server.
Clean Water Services, a stormwater management facility in Oregon, maintains about 1,000 bioswales every year. They visit each bioswale 3 to 4 times per year. The average cost to maintain these bioswales is around $275,000. Integrating my solution into the 1000 bioswales would cost about $140,000. I conservatively estimate the solution will save about 20% of the annual maintenance cost, and about one visit per year. That’s around $55,000 saved per year! In the lifespan of a bioswale, typically 20 to 50 years, this solution can save 1 to 2.75 million dollars. This solution has other benefits as well, such as addressing and preventing issues quicker, an abundance of data for improving future bioswales, and money savings to build more bioswales.
In the future, I can enhance the solution such that people living near bioswales can report on its condition. This is called crowdsourcing. Another improvement could be to integrate with Google Maps, so that when people pass by bioswales, information about them will come up to help increase the awareness of bioswales. The app could also integrate with weather reports and generate alerts or graphs for the dashboard. This could help be prepared for the weather conditions and maintenance afterwards. There could also be cameras that help check for litter and weeds.
Bioswales are effective and natural ways of filtering stormwater. However, their maintenance is a key problem. As a responsible citizen, it is our duty to protect them. This is made easy with “BioPro”. I believe with this one small step forward, we can make a great difference in the environment.
References:
Clean Water Hero. (n.d.). Retrieved from https://cleanwaterservices.org/wp-content/uploads/2022/06/pwqf-brochure.pdf
Cost Sheet. (n.d.). Retrieved from Green Values website: https://greenvalues.cnt.org/
Improving Water Efficiency. (n.d.). Retrieved from American Society of Landscape Architects website: https://www.asla.org/bioswales.aspx
Nir, S. M. (2017, March 23). To the City, a Pollution Fighter. To Some Residents, an Eyesore. Retrieved from The New York Times website: https://www.nytimes.com/2017/03/23/nyregion/bioswale-rain-gardens-new-york.html
Private Water Quality Facility Program. (n.d.). Retrieved from Clean Water Services website: https://cleanwaterservices.org/industry/pwqf/
Rain Garden Designs. (n.d.). Retrieved from Clean Water Services website: https://cleanwaterservices.org/community-home/resources/yard/stream-friendly/rain-gardens/