These are concurrent tracks – you’ll able to choose which track you want to attend on the day of the event.
By: Alex McLemore, Research Engineer, Oklahoma State University
Additional Authors: Jason R. Vogel, Reid Coffman, John McMaine, Glenn Brown, Michelle Melone
A suburban neighborhood in Oklahoma City, OK was selected as a demonstration site for five bioretention cells of varying types and scales to reduce phosphorus and sediment loading in Hog Creek and Lake Thunderbird. Both Hog Creek and Lake Thunderbird are on the EPA 303(d) list for low dissolved oxygen and turbidity, both of which are influenced by high levels of sediment and phosphorus. Of the five bioretention cells, three range in size from 200 to 800 s.f. ,were designed to treat sub-catchment areas targeting locations with erosion and drainage issues, and to add to the aesthetics to the landscape. The fourth project replaced 125 feet of a concrete stormwater channel with a series of biofiltration vanes, a combination of a bioretention cell and stream restoration techniques. The fifth bioretention cell is 8500 s.f. and designed to capture excess irrigation water and storm events for an 8 acre catchment. This large cell is aesthetically similar to a golf green but functions as a bioretention cell during storm events. Construction of these cells was completed in the spring of 2014. In addition to the construction, the large “golf green style” bioretention cell was monitored for stormwater quality in 2015. Results indicated positive concentration reductions for most parameters measured. Dissolved phosphorus concentration was reduced by 65% and total phosphorus concentration reduced by 61% from the inlet to the underdrain. Turbidity and Total Suspended Solids were both reduced by 64%.
By: Matt Willis, Regional Sales Manager, OptiRTC
Additional Authors: Jamie Lefkowitz
Traditional Green and Gray Stormwater BMP’s have historically been designed as passive systems governed by a fixed control structure designed to achieve a target water quality and/or quantity objective (i.e., treatment volume, attenuation). Passive systems however, rarely represent optimal solutions.
Due to the advances in low cost, internet accessible controller systems and wired and wireless communications, there are now reliable, robust, and secure solutions for cost effective continuous monitoring and adaptive control (CMAC) of stormwater infrastructure. These technologies allow BMPs to be monitored and controlled in real time via the internet. CMAC solutions integrate information directly from field deployed sensors with real-time weather forecast data (i.e., NOAA forecasts) to directly monitor performance and make automated and predictive control decisions to actively manage stormwater storage and flows.
Specifically, CMAC BMPs can improve environmental outcomes by:
– Using a facility’s storage volume to detain flow across all storm sizes.
– Dramatically improving water quality from facilities by increasing residence time and/or improving unit process effectiveness (e.g., settling, denitrification).
– Restoring pre-development hydrology and base flows by actively modulating release rates based on forecast information.
– Increasing the volume retained on site.
– Intelligently detaining flows in combined sewer systems for release during dry weather.
– Reduce the frequency of flooding events.
– Enabling durable and adaptable designs that are less dependent on site specific conditions.
– Being adaptable to future climatic conditions or changes in site characteristics without new infrastructure and with only operational changes.
This active water management solution is particularly effective in Low Impact Development projects, where the goal is managing storm water closer to the source.
By: David Rus, Hydrologist, US Geological Survey
Additional Authors: Andy Szatko (City of Omaha), Brenda Groskinsky (US EPA), Kellan Strauch (USGS), William Shuster (US EPA)
Green infrastructure (GI) is gaining consideration as an effective form of stormwater management, especially in communities like Omaha, Nebraska that are faced with combined sewer overflow issues. The main theme of our study is characterizing the linkage between GI design factors and the performance of that GI. The US Environmental Protection Agency (USEPA) and the US Geological Survey (USGS) are assessing soil characteristics and monitoring GI performance in several locations nationwide to support GI design guidelines that account for factors that are unique to a region. One of these locations is in Omaha, Nebraska, where a cooperative monitoring project between the City of Omaha, the USEPA, and the USGS has been established for a bioretention cell. Monitoring has focused on an assessment of the water balance in the cell, and a characterization of soil moisture around the cell. This monitoring design was made possible because strong communication was maintained among the partner agencies, the design team, and the contractors before and during construction. The implementation of that monitoring has not been without challenges, and the lessons that have been learned contribute to ongoing improvement in the form and function of GI. However, preliminary monitoring results are being used to develop a practical understanding of good monitoring practices and local hydrologic sinks and sources, such as insights related to infiltration characteristics in the clay loam soils. This information will ultimately be leveraged toward effective stormwater management.