Minnesota Water Resources Conference - Water Resources Center ...

Poster Session 4:45–5:45
BOOK OF ABSTRACTS
Tuesday, Monday, October 27 23
Stream Bed Slope Response to Gravel and Sand
John Gaffney, St. Anthony Falls Laboratory, gaff0050@umn.edu; Kimberly Hill, St. Anthony Falls Laboratory; Chris Paola, St.
Anthony Falls Laboratory
Best practice in stream restoration requires prediction of the stable slope of a gravel bed river on the basis of
specified sediment sizes. However, a restored gravel bed will likely be subjected to influxes of finer sediments
and the resulting bed slope is largely unknown. We report on experiments designed to study the slope response
of a gravel bed river to an influx of sediments finer than those present in the bed. We compare the slope of a
gravel feed system to the slope produced after doubling the total feed rate by adding finer sediment at a rate
equal to the original gravel feed. We frame our experimental results using theoretical predictions that (1) for
size ratios close to 1 the bed slope will increase, (2) for intermediate size ratios the bed slope will decrease and
(3) for very large size ratios the bed slope will be unchanged.
Water Quality in Saint Paul: BMP Cards as Education/Outreach Tool
Joni Giese, SRF Consulting Group Inc., jgiese@srfconsulting.com; Tim Griffin, Saint Paul on the Mississippi Design Center
Objectives
Although existing water quality manuals contain useful technical information, they are not easily understood
by residents or policy-makers. Therefore, water quality best management practice (BMP) cards were developed
by the Saint Paul on the Mississippi Design Center to present water quality concepts, treatment strategies,
and design approaches in an illustrative and easily understood format. These interactive cards educate
policy-makers and city residents about the important relationship between water quality and the health of the
Mississippi River.
Methodologies
The cards are designed to initiate a conversation at the beginning of the design process, not to provide detailed
guidance. Each card provides a basic BMP illustration, definition, associated treatment goals, a local example,
and additional technical resources.
Results
The presenters will describe how the cards have been received by the community and how the Design Center
has used the cards as part of their design workshop process.
Bacterial Encapsulation for PCB Degradation
Jenny Grady, University of Minnesota, grady038@umn.edu; Erin Surdo, University of Minnesota; Bill Arnold, University of
Minnesota; Paige Novak, University of Minnesota
Polychlorinated biphenyl (PCB) contamination is a persistent and widespread problem in lake, river, marine,
and estuarine sediment. Biodegradation is severely limited by the bioavailability of PCBs, which results in
a low population of organisms capable of degrading or dechlorinating PCBs. Our research focuses on the
development of a novel membrane system that would deliver a large population of aerobic PCB degrading
bacteria (Burkholderia xenovorans strain LB400) along with oxygen to the contaminated sediment, providing an
environment where growth and survivability were enhanced. Coupled with an abiotic containment membrane,
the technology would both remediate and contain PCB contamination. Data on the PCB degradation capability
of LB400 and the viability of polyacrylamide-encapsulated LB400 over time will be presented.
Minnesota Water Resources Conference, October 27–28, 20078 40