Water Resources - IMPACT - September 2017 - 27

* Biological transformations.
These mechanisms are capable
of providing moderate to high
treatment efficiencies for total
nitrogen and total phosphorus.
Treatment can be maximized
by optimizing important
system variables such as MAR
geometric layout, soil hydraulic
conductivity, water loading rate,
water temperature, vadose zone
thickness, and contact time. These
projects also need to be managed to
minimize soil clogging over time as
this can affect the overall treatment
capacity of the systems. Two MAR
projects in Florida provide good
examples of the potential water
quality benefits.
The first project is located
in Martin County, Florida,
adjacent to the St. Lucie Canal
and was constructed as part of
the "dispersed water management
program" administered by the
South Florida Water Management
District (SFWMD). This project,
the "water farm," is intended to
provide a means to store and recharge
stormwater containing high nutrient
concentrations on private land in order to
minimize releases of these contaminated
waters to nearby estuaries. The first phase
of the project included a 419 acre pilot
MAR site recharging stormwater into the
surficial aquifer system. The University of
North Florida (UNF) recently published a
report (UNF 2015) summarizing the water
farm performance during a pilot period
from February 2014 through April 15, 2015.
During the pilot period, the water farm was
able to store 18,261 acre-feet or 5.95 billion
gallons of water pumped from the St. Lucie
Canal. About 82% of the stored water was
infiltrated into the surficial aquifer system,
with the remainder lost through evaporation
or placed into temporary above-ground
storage. Further, UNF estimates that this
MAR project removed 2.66 metric tonnes
of phosphorus and 13.10 metric tonnes of
total nitrogen from February 2014 to March
31, 2015. In addition, the unit cost of storage
was very low, estimated to be only $37 per
acre-foot of water for the pilot project.
Based upon the excellent performance of
this MAR pilot project, the water farm is
currently being expanded to a much larger

Figure 1. One possible layout of expanded
MAR project.

footprint. Ultimately, it is envisioned that
this project could be more than 2,000 acres
in size. UNF estimates that the larger water
farm will be capable of removing 50% of the
total nitrogen of the stormwater influent and
up to 75% of the total phosphorus. Further
field studies at the project site are needed to
verify this estimate but the design team is
optimistic that those water treatment goals
can be achieved. Figure 1 shows one of the
proposed layouts for the expanded water
farm project.
The second MAR project of interest
in this discussion is the Kissimmee River
ASR project located on the north side of
Lake Okeechobee where the Kissimmee
River discharges to the lake. This ASR pilot
project is a component of the Everglades
Restoration and has a nominal recharge/
recovery capacity of 5 million gallons per
day (MGD). In depth pilot testing conducted
by the SFWMD and the U.S. Army Corps
of Engineers (USACE) was completed over
the last decade. Overall, the pilot studies
were very successful and provided USACE
and SFWMD scientists with considerable
knowledge. Pilot testing confirmed that the
project could indeed recharge stormwater

and recover it at the same well at
a rate of 5 MGD. The pilot project
also provided critical design
information needed by the USACE
and SFWMD regarding scaling up
the ASR project to a much larger
size. Future project expansions may
result in 5 to 10 more ASR wells
at the same site. One unexpected
benefit that was discovered was that
the project resulted in significant
nutrient reduction. A review of
all ASR efforts for the Everglades
Restoration was recently conducted
by the National Research Council
(https://www.nap.edu/read/21724/
chapter/2). This review noted
that the "removal of phosphorus
represents a key unexplored benefit
of ASR, and more research is needed
to examine the long-term rates and
extents of subsurface phosphorus
removal under various aquifer
conditions." Further study regarding
the nutrient removal efficiency of
ASR MAR projects certainly seems
warranted.
In summary, MAR projects
provide a host of benefits to proponents
including the ability to reduce nutrients.
As nutrient reduction becomes more of a
regulatory focus across the United States,
MAR projects will be increasingly viewed
as a viable alternative to achieve reduction
goals. So let's put aquifers to work! ■
Chris Brown is an associate professor at the
University of North Florida in Jacksonville,
Florida. he teaches water resources,
geotechnical, and civil design courses for
both undergraduate and graduate students.
Brown has taught for almost 12 years. Prior
to joining the academic world, He worked for
the U.S. Army Corps of Engineers and Golder
Associates, Inc. for almost 20 years working
on large public works projects across the
United States. Contact: christopher.j.brown@
unf.edu.

References
Kruzic, A., 1997. Natural treatment and onsite
processes, Water Environment Research, 69(4):522-526.
Liehr, S., 2005. Natural treatment and onsite processes
review, Water Environment Research, 77(6):1389-1424.
Stable URL: http://www.jstor.org/stable/29763729
UNF, 2015. An Independent Technical Assessment of
Martin County, Florida Water Farming Pilot Project, UNF
Research Report, 54 p. DOI: 10.13140/RG.2.2.18186.47047

Volume 19 * Number 5 www.awra.org * 27


https://www.nap.edu/read/21724/ http://www.jstor.org/stable/29763729 http://www.awra.org

Table of Contents for the Digital Edition of Water Resources - IMPACT - September 2017

President’s Message
Growing Up…with Managed Aquifer Recharge
Aquifer Storage and Recovery as Means to
The Regulatory Environment of Managed
The ASCE-EWRI Standard Guidelines
Managed Aquifer Recharge:
Managed Aquifer Recharge: A Global Perspective
What’s Up with Water? Sisyphus, Heraclitus and WOTUS
The New Economics of Water: Reducing CO2 Emissions in the Bay Delta Could Reverse Erosion
Domestic Well Aquifer Storage and Recovery Using Seasonal Springs
Philosophy and Ethics: The Rio Grande and the Ganges Rivers: How Human ‘Success’ is Choking the Life out of Two Great River-Spirits
ASR: Aquifer Storage Rescues a Small Water Supply District
Putting Aquifers to Work: MAR Applications in Nutrient Removal
Summer Conference Recap
Harvesting Glacial Meltwater with Managed Aquifer Recharge
AWRA State Section and Student Chapter News
In Memoriam: Peter E. Black
Herbert Scholarship Award Recipients for 2017-2018 Announced
August JAWRA Highlights
2017-2018 Editorial Calendar
Water Resources - IMPACT - September 2017 - intro
Water Resources - IMPACT - September 2017 - cover1
Water Resources - IMPACT - September 2017 - cover2
Water Resources - IMPACT - September 2017 - 3
Water Resources - IMPACT - September 2017 - 4
Water Resources - IMPACT - September 2017 - President’s Message
Water Resources - IMPACT - September 2017 - Growing Up…with Managed Aquifer Recharge
Water Resources - IMPACT - September 2017 - 7
Water Resources - IMPACT - September 2017 - Aquifer Storage and Recovery as Means to
Water Resources - IMPACT - September 2017 - 9
Water Resources - IMPACT - September 2017 - 10
Water Resources - IMPACT - September 2017 - The Regulatory Environment of Managed
Water Resources - IMPACT - September 2017 - 12
Water Resources - IMPACT - September 2017 - 13
Water Resources - IMPACT - September 2017 - The ASCE-EWRI Standard Guidelines
Water Resources - IMPACT - September 2017 - 15
Water Resources - IMPACT - September 2017 - 16
Water Resources - IMPACT - September 2017 - Managed Aquifer Recharge:
Water Resources - IMPACT - September 2017 - 18
Water Resources - IMPACT - September 2017 - 19
Water Resources - IMPACT - September 2017 - Managed Aquifer Recharge: A Global Perspective
Water Resources - IMPACT - September 2017 - 21
Water Resources - IMPACT - September 2017 - 22
Water Resources - IMPACT - September 2017 - 23
Water Resources - IMPACT - September 2017 - 24
Water Resources - IMPACT - September 2017 - 25
Water Resources - IMPACT - September 2017 - 26
Water Resources - IMPACT - September 2017 - 27
Water Resources - IMPACT - September 2017 - 28
Water Resources - IMPACT - September 2017 - 29
Water Resources - IMPACT - September 2017 - What’s Up with Water? Sisyphus, Heraclitus and WOTUS
Water Resources - IMPACT - September 2017 - 31
Water Resources - IMPACT - September 2017 - The New Economics of Water: Reducing CO2 Emissions in the Bay Delta Could Reverse Erosion
Water Resources - IMPACT - September 2017 - Philosophy and Ethics: The Rio Grande and the Ganges Rivers: How Human ‘Success’ is Choking the Life out of Two Great River-Spirits
Water Resources - IMPACT - September 2017 - ASR: Aquifer Storage Rescues a Small Water Supply District
Water Resources - IMPACT - September 2017 - 35
Water Resources - IMPACT - September 2017 - Summer Conference Recap
Water Resources - IMPACT - September 2017 - 37
Water Resources - IMPACT - September 2017 - AWRA State Section and Student Chapter News
Water Resources - IMPACT - September 2017 - In Memoriam: Peter E. Black
Water Resources - IMPACT - September 2017 - Herbert Scholarship Award Recipients for 2017-2018 Announced
Water Resources - IMPACT - September 2017 - 41
Water Resources - IMPACT - September 2017 - 2017-2018 Editorial Calendar
Water Resources - IMPACT - September 2017 - cover3
Water Resources - IMPACT - September 2017 - cover4
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