First Advisor

William Fish

Term of Graduation

Winter 2022

Date of Publication

3-29-2022

Document Type

Thesis

Degree Name

Master of Science (M.S.) in Civil & Environmental Engineering

Department

Civil and Environmental Engineering

Language

English

DOI

10.15760/etd.7797

Physical Description

1 online resource (viii, 118 pages)

Abstract

Stormwater control measure (SCM) performance is well studied regarding solids removal; however, analysis of mass loading capacity, long-term performance, and maintenance demands are challenging due to the variability and multiple constituents inherent in urban stormwater. This research examines the long-term water quality performance and sediment mass capacity of two common SCMs: high rate biofiltration (HRBF) and conventional bioretention (BRT). Pollutant removal trials were conducted in a laboratory setting per the New Jersey Department of Environmental Protection (NJDEP) filtration protocol in two phases: the first using inorganic sediment per the NJDEP protocol, the second phase with the addition of organic sediment and hydrocarbons, which are hypothesized to significantly affect maintenance and life cycle of filtration systems, and also better represent the response of SCMs to urban stormwater constituents. HRBF and BRT systems were evaluated using sediment mass loading vs. the maximum treatment flow rate, sediment mass loading vs. head loss, and sediment mass loading vs. removal efficiency. HRBF-1 trials treated 22.9 lb/ft2 of inorganic test sediment before bypass occurred at the maximum treatment flow rate (MTFR), with an average total suspended solids (TSS) removal efficiency (RE) of 77.2%. HRBF-2 trials treated 1.9 lb/ft2 of inorganic/organic/oil test sediment before bypassing at the MTFR, with an average TSS RE of 90.1%. BRT-1 trials with inorganic sediment were concluded prior to bypass or other failure modes, with 3" of head loss observed at 1.8 lb/ft2 of test sediment loading and a TSS RE of 97.9%. BRT-2 trials were concluded when the MTFR dropped below 90% MTFR, with 5" of head loss observed at 0.39 lb/ft2 of inorganic/organic/oil loading, and an average TSS RE of 80.6%. Results suggest that the mass capacity and long-term performance of these SCMs can differ by an order of magnitude with the addition of organic and hydrocarbon constituents to inorganic test sediment. Additionally, both SCMs were compared on an estimated annual mass retained basis, using the mass loading test results, with the normalized HRBF-2 and BRT-2 columns retaining 1.7 lb/ft2 and 0.31 lb/ft2, respectively, of inorganic and organic sediment. Oil loading prior to concluding testing was 22.9 g/ft2 for HRBF-2 and 2.99 g/ft2 for BRT-2. The BRT-2 test media demonstrated significant media washout, with an estimated 7.0 lb of TSS being exported prior to starting RE trials. Due to media washout, BRT-2 also could not meet the NJDEP 80% TSS removal for the first ten trials, with an average TSS RE of 69.8%. While not a focus of this research, BRT effluent was tested for total phosphorus (TP) and dissolved phosphorus (DP) due to the observed effluent having a consistent yellow discoloration. BRT test columns demonstrated a maximum TP export of 3.80 mg/L and a minimum TP export of 0.892 mg/L, with a mean DP:TP of 84%. Results suggest that better quality assurance and control of BRT media can improve water quality outcomes. Mass capacity trial results can better inform the design of HRBF and BRT systems for long-term performance and better inform regulators in creating policy to meet Clean Water Act goals. Understanding the long-term performance and maintenance demands of SCMs is critical for advancing stormwater management methods and protecting our water resources.

Rights

© 2022 Craig Michael Fairbaugh

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

Persistent Identifier

https://archives.pdx.edu/ds/psu/37385

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