Ruben Kertesz

Bhadha, Jehangir H., Casey Schmidt, Robert Rooney, Paul Indeglia, Ruben Kertesz, Elizabeth Bevc, and John Sansalone, 2009. Granulometric and Metal Distributions for Post‐Katrina Surficial Particulate Matter Recovered From New Orleans. Journal of the American Water Resources Association (JAWRA) 45(6):1434‐1447.:  Hurricane Katrina and the resulting failure of the levees that surrounded and protected New Orleans generated a significant detained volume of stormwater within the urban area of New Orleans. Between the inundation resulting from levee failure and eventual pumped evacuation of stormwater from the urban area of New Orleans, a large mass of storm‐entrained particulate matter (PM) was deposited in the inundated areas. This study examined the granulometry and granulometric distribution of metals for post‐Katrina surficial PM deposits recovered from 15 sites (10 inundated and 5 non‐inundated) in New Orleans. Results of this examination were compared to pre‐Katrina data from New Orleans. While post‐Katrina analysis of PM indicates that Pb, Zn, and Cu concentrations for PM are reduced for all sites, inundated sites had higher Cu, Pb, and Zn concentrations for the settleable (∼25‐75 μm) and sediment (>75 μm) size fractions. A comparison between total metal concentration and the bioavailable (leachable) fraction for PM reveals that inundated sites had up to 19% higher leachable metal concentration compared to non‐inundated sites. The reduction in PM‐bound total metal concentrations for recovered PM can be explained through a combination of scouring (and therefore change in granulometry from pre‐Katrina) that resulted from transport of suspended PM by storm flows and pumped evacuation; as well as leaching and PM‐based redistribution from extended contact with rainfall and during stormwater detention. New Orleans has been exposed to elevated levels of metals through decades of activities that include vehicular transportation, chemical, industrial, and oil production facilities resulting in higher metal concentrations for urban soil‐residual complexes. As a result, the influent storm flows associated with Katrina as an episodic event cannot solely explain the distribution and fate of PM‐associated metal concentrations.

Impervious surfaces alter hydrology while affecting the chemical balance of water resources. Even though historical flooding remains an issue, chemistry, loads, and aesthetics are companion concerns. Recently, total maximum daily loads have spread across the United States. Additionally, Florida has promulgated no net load increases for runoff and constituents and now has numeric criteria for nutrients. As trends move toward low-impact development and green infrastructure, urban retrofit design practice entails hydrologic restoration, reuse, and source control. Site redesign can provide a means to manage hydrologic and constituent load, with no net increase for long-term loadings. The proposed design retrofitted an existing surface parking facility with a series of design elements. A biofiltration area reactor was lined with clay for management of the water table and denitrification. A linear infiltration reactor of cementitious permeable pavement provided infiltration and evaporation, filtration, and adsorption. Street sweeping provided source control. In addition, load credits have been established in Florida for nutrients recovered from street sweeping. Continuous simulations with climate and site data indicated that redesign could result in no load increase. Estimates demonstrated that the cost of redesign was comparable to conventional construction costs while incorporating a Florida-friendly landscape. Also, design options cost less per nutrient load treated than did conventional Florida best management practices.

The authors have used the CANARY event detection software for the purposes of detecting and identifying system response to rainfall in a permeable pavement stormwater best management practice that is installed in an academic parking lot in Cincinnati, OH. The results show that the software, originally designed for water quality detection in drinking water systems, proved adept at identifying a change in both underdrain flow and subsurface moisture in response to precipitation. Flow was measured as level in a 1-inch Parshall flume. Moisture was measured using four transmission line oscillation water content reflectometers placed in the aggregate media beneath interlocking concrete pavers. Of 21 storms greater than 2.5 mm of precipitation, all 21 were detected using CANARY software when evaluating flow detection. Nineteen of the 21 were detected using CANARY software to process the moisture signals. Additional event detections were generated from sensor device failures and maintenance activity.

Computational fluid dynamics (CFD) is an emerging tool to predict the coupled hydrodynamics and particulate matter (PM) fate in unit operations (UOs) subject to rainfall-runoff events. Most studies examine unit operations on an event-basis. This study also includes event-based analysis extended to time domain continuous simulation using the Stormwater Management Model (SWMM) to evaluate unit operation performance on a long-term basis with and without maintenance. A validated computational fluid dynamics model simulated particulate matter fate in a rectangular clarifier (RC) and a screened hydrodynamic separator (SHS) for a representative year of runoff in a North Florida source area. The clarifier and SHS are fundamentally different unit operations with differing behavior, applications and functionality. The objective of the study is to illustrate the modeling of these two unique, but common units. The large footprint clarifier with volumetric capacity is a primary treatment unit operation while the SHS is a pretreatment gross solids trap without storage. Results indicate that the SHS is prone to washout without frequent maintenance. While neglecting particulate matter washout from the SHS overestimates SHS annual performance this was not the case for the clarifier. For unit operations, computational fluid dynamics and time domain continuous simulation models are tools to estimate fate of particulate matter and nutrients on an annual basis. Examined on an annual basis the mean cost (USD) to recover 1.0 lb (0.45 kg) of particulate matter (PM) (irrespective of particle size since the SHS is a gross solids trap) is $4 (SHS), $10 (clarifier) and for comparison, $15 (radial cartridge filter) without pre- or primary treatment required (and associated costs) by such filters. This compares to street sweeping at $0.10 to recover 1.0 lb of PM.

As regulatory pressure to reduce the environmental impact of urban stormwater intensifies, US municipalities increasingly seek a dedicated source of funding for stormwater programs, such as a stormwater utility. In rare instances, single family residences are eligible for utility discounts for installing green infrastructure. This study examined the hydrologic and economic efficacy of four such programs at the parcel scale: Cleveland (OH), Portland (OR), Fort Myers (FL), and Lynchburg (VA). Simulations were performed to model the reduction in stormwater runoff by implementing bioretention on a typical residential property according to extant administrative rules. The EPA National Stormwater Calculator was used to perform pre- vs post-retrofit comparisons and to demonstrate its ease of use for possible use by other cities in utility planning. Although surface slope, soil type and infiltration rate, impervious area, and bioretention parameters were different across cities, our results...

The authors have used the CANARY event detection software for the purposes of detecting and identifying system response to rainfall in a permeable pavement stormwater best management practice that is installed in an academic parking lot in Cincinnati, OH. The results show that the software, originally designed for water quality detection in drinking water systems, proved adept at identifying a change in both underdrain flow and subsurface moisture in response to precipitation. Flow was measured as level in a 1-inch Parshall flume. Moisture was measured using four transmission line oscillation water content reflectometers placed in the aggregate media beneath interlocking concrete pavers. Of 21 storms greater than 2.5 mm of precipitation, all 21 were detected using CANARY software when evaluating flow detection. Nineteen of the 21 were detected using CANARY software to process the moisture signals. Additional event detections were generated from sensor device failures and maintenance activity.

Impervious surfaces alter hydrology while affecting the chemical balance of water resources. Even though historical flooding remains an issue, chemistry, loads, and aesthetics are companion concerns. Recently, total maximum daily loads have spread across the United States. Additionally, Florida has promulgated no net load increases for runoff and constituents and now has numeric criteria for nutrients. As trends move toward low-impact development and green infrastructure, urban retrofit design practice entails hydrologic restoration, reuse, and source control. Site redesign can provide a means to manage hydrologic and constituent load, with no net increase for long-term loadings. The proposed design retrofitted an existing surface parking facility with a series of design elements. A biofiltration area reactor was lined with clay for management of the water table and denitrification. A linear infiltration reactor of cementitious permeable pavement provided infiltration and evaporatio...

Bhadha, Jehangir H., Casey Schmidt, Robert Rooney, Paul Indeglia, Ruben Kertesz, Elizabeth Bevc, and John Sansalone, 2009. Granulometric and Metal Distributions for Post‐Katrina Surficial Particulate Matter Recovered From New Orleans. Journal of the American Water Resources Association (JAWRA) 45(6):1434‐1447.:  Hurricane Katrina and the resulting failure of the levees that surrounded and protected New Orleans generated a significant detained volume of stormwater within the urban area of New Orleans. Between the inundation resulting from levee failure and eventual pumped evacuation of stormwater from the urban area of New Orleans, a large mass of storm‐entrained particulate matter (PM) was deposited in the inundated areas. This study examined the granulometry and granulometric distribution of metals for post‐Katrina surficial PM deposits recovered from 15 sites (10 inundated and 5 non‐inundated) in New Orleans. Results of this examination were compared to pre‐Katrina data from New O...

The built environs alter hydrology and water resource chemistry. Florida is subject to nutrient criteria and is promulgating "no-net-load-increase" criteria for runoff and constituents (nutrients and particulate matter, PM). With such criteria, green infrastructure, hydrologic restoration, indirect reuse and source control are potential design solutions. The study simulates runoff and constituent load control through urban source area re-design to provide long-term "no-net-load-increases". A long-term continuous simulation of pre- and post-development response for an existing surface parking facility is quantified. Retrofits include a biofiltration area reactor (BAR) for hydrologic and denitrification control. A linear infiltration reactor (LIR) of cementitious permeable pavement (CPP) provides infiltration, adsorption and filtration. Pavement cleaning provided source control. Simulation of climate and source area data indicates re-design achieves "no-net-load-increases" at lower costs compared to standard construction. The retrofit system yields lower cost per nutrient load treated compared to Best Management Practices (BMPs).