Evaluating the impact of a constructed floodplain wetland on water quality in an urban stream in State College, PA
Open Access
Author:
Fan, Liyan
Graduate Program:
Environmental Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
June 29, 2021
Committee Members:
Patrick Fox, Program Head/Chair Lauren Mc Phillips, Thesis Advisor/Co-Advisor Li Li, Committee Member Nathaniel Richard Warner, Committee Member
Keywords:
Best Management Practice pollutants removal efficiency constructed floodplain wetlands Chesapeake Bay
Abstract:
This thesis is focused on evaluating water quality function of a constructed floodplain wetland
located along an urban stream in State College, Pennsylvania. Analysis of hydrology as well
as nitrogen, phosphor o us, and sediment patterns from baseflow and stormwater samples are
presented from multiple sites in the wetland and adjacent urban stream. The data
demonstrates that the wetland provides reduction in nitrogen and sed iments when it receives
water during baseflow periods, but no reduction for phosphorous. During storm events,
sediment (28~99%) and phosphorous (11~91% removal ratios in the wetland are high while
nitrogen removal is decent -16~47%). The wetland also ha s the function of stormwater runoff
removal (17~57%). The wetland has good nitrogen removal efficiency during P limitation time
and good Phosphorous removal efficiency during N limitation time. Thus, when evaluating
effectiveness of the constructed floodplain wetland as an individual unit, it performs well for
nutrient and sediment removal. However, given that the amount of water diverted from the
stream to the wetland is often between 1 5% of streamflow, depending on the magnitude of
streamflow, the wetlan d’s impact on the adjacent stream is low. It’s recommended to adjust
inlet design to increase the amount of water entering into the wetland.
