Congrats & au revoir to Melinda

Congratulations and a fond farewell to Melinda Marsh who has successfully defended and completed her masters thesis entitled: Using high-frequency data and concentration-discharge relationships to describe solute mobilization and transport in suburban and urban watersheds

Melinda’s very cool research is one of the first studies to use multiple ions and concentration-discharge (C-Q) relationships to investigate on the effects of impervious surface area in urban areas on solute mobilization and transport. Her next adventure is doing a Ph.D. at Penn State with Jon Duncan in the Watershed Ecohydrology and Biogeochemistry Lab.

New study on the effects of stream restoration

Patrick McMahon (ENVS M.S. ’20) is first author on a just-published Environmental Research Letters paper with several TU co-authors including other ENVS M.S. students about the effects of stream restoration (via the legacy sediment removal & floodplain reconnection approaches) on water quality at six restored reaches in Baltimore and Harford Counties in Maryland.

The paper is part of a Focus Issue on Legacy Effects of Land use and Management on Water Quality and Ecosystem Function that was edited by Nandita Basu, Kimberly Van Meter, Shree Inamdar, Elena Bennett, Emily Bernhardt, and Michelle McCrackin.

P. McMahon, V. B. Beauchamp, R. E. Casey, C. J. Salice, K. Bucher, M. Marsh, and J. Moore (2021) Effects of stream restoration by legacy sediment removal and floodplain reconnection on water quality. Environmental Research Letters. 16: 035009.

The effectiveness of many stream restorations in improving water quality is unmeasured. In the Mid-Atlantic region of the United States, activity by European settlers resulted in upland erosion and deposition of sediments 1–3 m in thickness in stream valleys. Subsequently, streams incised those legacy sediments creating steep, exposed banks, infrequent floodplain inundation, and water tables disconnected from floodplains. Legacy sediment removal (LSR) and floodplain reconnection (FR) proposes water quality improvement by restoration to a hydrological state closer to pre-European. We investigated water quality at nine sites, six restored with LSR/FR and three comparison sites. Nitrogen baseflow concentrations and fluxes were elevated in urban and agricultural watersheds with little apparent effect due to restoration. Denitrification appeared to be constrained by carbon availability. Ion concentrations were elevated in all watersheds compared to a forested reference and represent a substantial ecological stressor for the post-restoration aquatic community. Storm event data from one site suggest small reductions in nutrient and sediment loads across the restored reach. High-frequency time series indicate that restoration effects are not observable at larger scales. The effects of restoration, particularly for denitrification, may not be observable for years and can be obscured by weather and climate-driven variability.

Congratulations to Patrick

A huge congratulations to Patrick McMahon for successfully defending and completing his masters thesis entitled: Effects of stream restoration by legacy sediment removal and floodplain reconnection on water quality.

Patrick did excellent work studying the effects of stream restoration (via legacy sediment removal approach) at 6 sites in Baltimore County and Harford County, Maryland.

08/2021 update: Patrick started a job at Bluewater Baltimore.

NSF grant to study the urban Critical Zone

We received a National Science Foundation grant as part of a collaborative effort to study the urban Critical Zone over the next 5 years with a great group of colleagues from several universities: Network Cluster: Urban Critical Zone processes along the Piedmont-Coastal Plain transition. This research is part of NSF’s broader Critical Zone Cluster Network efforts.

Collaborators include:

  • Claire Welty (Project Director) & Andy Miller, University of Maryland–Baltimore County (UMBC)
  • Dan Bain, Univ. of Pittsburgh
  • Alan Berkowitz & Bess Caplan, Cary Institute
  • Jeff Chanat, Ed Doheny, Kristina Hopkins, & John Jastram, USGS
  • Jon Duncan, Penn State
  • Peter Groffman, CUNY
  • Mon-Han Huang &  Karen Prestegaard, University of Maryland–College Park
  • Laura Toran, Temple

Here is Towson’s write up about the project:

UMBC did a really nice write up:

High-frequency chloride & conductivity paper in ES&T

A paper with two USGS colleagues that is based on work that I did during my sabbatical (in 2018-19) was just accepted is now published at Environmental Science & Technology. I am really excited about this paper, which includes nearly 30 million observations, and is the broadest published study to date to quantify exceedances of the EPA aquatic life criteria for chloride.

High-frequency data reveal deicing salts drive elevated specific conductance and chloride along with pervasive and frequent exceedances of the U.S. Environmental Protection Agency aquatic life criteria for chloride in urban streams.
Moore J., Fanelli R. M., Sekellick A. J. (2020)
Environmental Science & Technology. 54: 778-789.

The data are visually summarized in a clickable map.

Increasing specific conductance (SC) and chloride concentrations [Cl] negatively affect many stream ecosystems. We characterized spatial variability in SC, [Cl], and exceedances of EPA [Cl] criteria using nearly 30 million high-frequency observations (2- to 15-minute intervals) for SC and modeled [Cl] from 93 sites across three regions in the eastern United States: Southeast, Mid-Atlantic, and New England. SC and [Cl] increase substantially from south to north and within regions with impervious surface cover (ISC). In the Southeast, [Cl] weakly correlates with ISC, no [Cl] exceedances occur, and [Cl] concentrations are constant with time. In the Mid-Atlantic and New England, [Cl] and [Cl] exceedances strongly correlate with ISC. [Cl] criteria are frequently exceeded at sites with greater than 9–10% ISC and median [Cl] higher than 30–80 mg/L. Tens to hundreds of [Cl] exceedances observed annually at most of these sites help explain previous research where stream ecosystems showed changes at (primarily non-winter) [Cl] as low as 30–40 mg/L. Mid-Atlantic chronic [Cl] exceedances occur primarily in December–March. In New England, exceedances are common in non-winter months. [Cl] is increasing at nearly all Mid-Atlantic and New England sites with the largest increases at sites with higher [Cl].

Related work:
USGS data release
Fanelli, Sekellick, and Moore (2019) Discrete and high-frequency chloride (Cl) and specific conductance (SC) data sets and Cl-SC regression equations used for analysis of 93 USGS water quality monitoring stations in the eastern United States

Updated 01/26/2021: This paper is now open access and thus freely available to all. Also, I added the plots for the regional chloride versus specific conductance relationships (with linear regression results also found in Table S10 of Supporting Information) below.



1)  Single linear regression

Southeast single linear regression

2) Piecewise regression

Southeast piecewise regression



1)  Single linear regression

Southeast single linear regression

2) Piecewise regression

Mid-Atlantic piecewise regression


New England

1)  Single linear regression – includes only data with SC <20,000 µS/cm

New England single linear regression (<20,000 µS/cm)

2) Piecewise regression – includes only data with SC <20,000 µS/cm

New England piecewise regression (<20,000 µS/cm)

3)  Single linear regression – includes all data

New England single linear regression (all data)

4) Piecewise regression – includes all data

New England piecewise regression (all data)

Presentations at 2019 AGU

Two M.S. students – Melinda Marsh and Patrick McMahon – from the lab will present at AGU this week. Their posters, along with collaborator Vanessa Beauchamp’s and mine, can seen on Wednesday afternoon in session H33J A Race Against Time: Legacy Effects of Land Use on Water Quality, Watershed Processes, and Ecosystem Function II Posters

Melinda, a first-year M.S. student, will be presenting on using concentration-discharge relationships to better understand solute transport in urban watersheds. Her poster is entitled: H33J-2076 Using High-Frequency Data and Concentration-Discharge Relationships to Describe Solute Mobilization and Transport in Suburban and Urban Watersheds

Patrick will be presenting on the effects of the legacy sediment removal approach to restoration on nitrogen and sediment in 6 watersheds. His poster is entitled: H33J-2057 Export of Nitrogen and Sediments Following Legacy Sediment Removal and Floodplain Reconnection Restoration Projects.

I will be presenting a poster on behalf of Vanessa Beauchamp, graduated M.S. student Patrick Baltzer, and myself entitled: H33J-2069 – Riparian Vegetation Community Composition After Legacy Sediment Removal and Floodplain Reconnection Projects

I also will be presenting a poster on work from my 2018-19 sabbatical, done in part at the MD-DE-DC Water Science Center of the USGS. We used a dataset with nearly 30 million observations to characterize conductivity and chloride concentrations as a function of urbanization within 3 regions in the eastern US and to quantify exceedances of the EPA chloride criteria in a poster entitled: H33J-2061 – High-Frequency Data Reveals Deicing Salt Application Causes Elevated and Increasing Conductivity and Chloride along with Widespread Exceedances of Chloride Water Quality Criteria in Urban Eastern US Streams.

Fond farewell to Ginny Jeppi

We’re sad to say good bye to Ginny Jeppi who finished in the Moore lab and the Beauchamp lab after 2.5 years as an undergraduate research assistant. Ginny was the first student to start working on the water quality portion of our Chesapeake Bay Trust grant to study the effects of stream restoration via legacy sediment removal.

Ginny will continue study stream restoration as she starts her Ph.D. in Shree Inamdar’s lab, supported by UNIDEL fellowship. at the University of Delaware.

Poster presentations at 2018 AGU

Three students, two undergraduate and one graduate, from the lab  presented poster at the 2018 American Geophysical Union (AGU) meeting in Washington, DC.  Ginny Jeppi and Patrick McMahon presented preliminary data on the effectiveness of the legacy sediment approach to stream restoration in reducing nutrient and sediment fluxes (funded by the Chesapeake Bay Trust). Melinda Marsh presented on concentration-discharge relationships in local urban streams (funded by NSF).

Additionally, Cassie Cosans (Ph.D. student at Johns Hopkins University [JHU] with Ciaran Harman) gave an oral presentation on which I was a co-author along with Ciaran and Maya Gomes (JHU).

Melinda presenting her poster


Presentations at 2018 MWMC

Two undergraduate and one graduate student from the lab – Ginny Jeppi, Melinda Marsh, and Patrick McMahon – presented at the 2018 Annual meeting of the Maryland Water Monitoring Council. Ginny gave an oral presentation while Melinda and Patrick gave poster presentations. Ginny and Patrick presented data about a research project funded by the Chesapeake Bay Trust to assess the effectiveness of stream restoration in reducing nutrient and sediment fluxes. Melinda presented work funded by a NSF grant on concentration-discharge relationships in local urban streams.

I presented on some of my sabbatical research about using high-frequency specific conductance data from the USGS to quantify exceedences of EPA aquatic life criteria for chloride. Rosemary Fanelli from the USGS was my co-author.