With roughly three fourths of the planet’s wetlands disturbed by humans, constructed urban wetlands are becoming increasingly prevalent. These wetlands help manage urban wastewater and provide many ecosystem services, including water quality improvement, carbon sequestration, and flood control. Suspended sediments are a common pollutant in urban wastewater that can degrade a wetland’s natural filtering capabilities and can potentially bury the wetland if not managed correctly. Luckily, advances in sensor-monitoring technology may give scientists and engineers the tools they need to create wetlands that allow sediments to flow through the wetland without compromising the filtering processes. The Cleveland Metroparks Watershed Stewardship Center, located in northeast Ohio, wished to assess the flow of sediment through a series of on-site constructed wetlands in response to a nearby landfill. To measure how effectively sediment was passing through the wetlands, two popular sampling methods were employed: manually collected total suspended solids (TSS) and turbidity data collected via sensors. Using the sensor data and volunteer-collected TSS data, we assessed the relationship between the two sampling methods to develop a sensor-collected proxy for suspended sediments measurements. We found an average turbidity reading of 1,012 NTU (standard deviation, N=27,971), while TSS averaged 85+/- 104 mg/L (standard deviation, N=10). Combining high-temporal resolution sensor-detected proxy measurements with more labor intensive, but more coarsely resolved direct measurements is an effective strategy for monitoring the water quality function of constructed wetlands. This will be critical to ensuring usable freshwater for future generations as the human species continues to spread across the earth.
Wetlands provide critical functions for human beings, including water quality improvement, carbon sequestration, and flood control. Yet, as cities grow, wetlands tend to disappear. As a result, constructed wetlands have become increasingly popular in urban areas. However, mimicking mother nature is no easy task. Wetlands can often be overburdened, or even buried, by sediments suspended in urban wastewater. To assess how sediments flow through constructed wetlands, researchers at KSU have partnered with the Cleveland Metroparks to employ two common sampling methods – automatic-sensor collected turbidity data and manually collected total suspended solids data – to develop a proxy between them. Developing proxies to allow increased usage of sensors will helps scientists and engineers design more efficient wetlands. This will be essential for preserving freshwater for future generations.