Solving the Water Quality Issue Rania Odeh

OXYGEN FOR LAKE
MERRITT
Solving the Water Quality Issue
Rania Odeh
LAKE MERRITT
■ East of downtown Oakland
■ 140 acre lagoon estuary fed by bay (approx.
1100 acre ft.)
■ The total watershed: 4650 acres.
HISTORICAL CONDITIONS OF WATER
QUALITY AT SITE
■ 1869: the 12th street dam was completed
HISTORICAL CONDITIONS OF WATER
QUALITY AT SITE
■ 1926: second set of tide gates installed at 8th street
HISTORICAL CONDITIONS OF WATER
QUALITY AT SITE
■ County of Alameda
allowed more frequent
tidal flows in the 1980’s.
■ New flood control policy
kept flood gates closed
during high tides and
heavy rains
■ Sewer repair
HISTORICAL CONDITIONS OF WATER
QUALITY AT SITE
■ 1993: channel to bay was filled and
narrowed, restricting the lake to 1-2’ of tidal
influence per day
■ high flood risk
■ Low DO, high temperature, high salinity
■ Current policy allows limited tidal flows
WATER QUALITY ISSUES:
DISSOLVED OXYGEN
■ DO = most important
factor for healthy
wildlife habitat and
overall water quality.
■ Oxygen depletion:
– tidal flow restriction
– excess of algal
blooms
WATER QUALITY ISSUES:
DISSOLVED OXYGEN
■ Aquatic species need
sufficient levels of
dissolved oxygen (DO)
to survive.
■ (DO) < 3ppm will stress
most warm water fish
species
■ < 2ppm will kill most
fish species
WATER QUALITY ISSUES:
DISSOLVED OXYGEN
■ water quality has been under close
monitoring for the past year by Amec Foster
Wheeler
■ data for both dissolved oxygen and salinity.
■ data collected from 2014-2015.
WATER QUALITY ISSUES:
DISSOLVED OXYGEN
■ three fountains installed in
1995-1999 by the Lake
Merritt institute to improve
the DO levels of the lake.
■ Each fountain only has
capacity to process 1 acre ft
of water per day; lake is
approx 1100 acre ft in total
WATER QUALITY ISSUES:
SALINITY
■ Estuary salinity range: .5 to 35
ppt.
■ Ocean water avg: 35 ppt
■ High salinity = uninhabitable
waters for fresh water + brackish
fish species + vegetation
■ Lack of tidal flushing + increased
temperatures and drought =
salinity level to exceed ocean
water
WATER QUALITY ISSUES:
SALINITY
■ Salinity has a major effect on DO levels within
estuaries
■ The solubility of oxygen in seawater is roughly 20
percent less than it is in fresh water at an equal
temperature
PROJECTED ISSUES WITH CONTINUED
STATUS OF POOR WATER QUALITY
■Biodiversity diminished
■Bad odor
■Potential affect on public health
MITIGATION METHODS FOR POOR
WATER QUALITY
■Raingardens
■Phytoremediation Ponds/Plants
■Oxygenating Plants
■Oyster Reefs
MITIGATION METHODS FOR POOR WATER
QUALITY: RAINGARDENS
■ Imitate water filtering
processes of wetlands
■ Situating rain gardens around
the lake would help improve
water quality, increase habitat
area for bird + insect species
+ increase recreational area +
add another aesthetic quality
to the park
MITIGATION METHODS FOR POOR
WATER QUALITY: PHYTOREMEDIATION
■ Phytoremediation: method of
bioremediation in which
contaminants in soil and water
are either removed, immobilized
or destroyed, using mainly plant
matter to complete the
processes
– Rhizofiltration
– phyto-volatization
– phyto-degradation
MITIGATION METHODS FOR POOR
WATER QUALITY: PHYTOREMEDIATION
■
■
■
■
Phytoplankton
Halophytes
Oxygenating species
Excessive phytoplankton is
high risk: trash, animal
refuse (Canada Geese),
sewage spillover from the
connected culverts
MITIGATION METHODS FOR POOR
WATER QUALITY: OXYGENATING PLANTS
■ Submerged/oxygenating water plants help filter
contaminants from water and provide oxygen.
■ Submerged plants provide shelter and DO for
fish and aquatic species to thrive; while
controlling phytoplankton growth.
Swamp Ludwigia
Water Hyssop
Water Ribbon
Parrot Feather
American Pondweed
Star Grass
MITIGATION METHODS FOR POOR
WATER QUALITY: OYSTERS
■ Single oyster can filter approx
30 gallons of water per day
■ filter all organic matter
through the digestive system
as food
– phytoplankton/algae, finegrained particulate, fecal
matter, bacteria
– nitrogen and phosphorous
OAKLAND’S MITIGATION STRATEGIES:
MEASURE DD
■ Replace 12th Street culvert w/ arched bridge to increase
tidal flow and flushing
■ Water quality improvements: storm water filters, trash
barriers, wildlife waste clean-up facilities, aeration fountains
■ Land acquisition for environmental clean up and
conservation
■ Hazardous materials clean up
■ Removal of 10th Street culvert
■ Relocation of flood control barrier at 7th Street
OAKLAND’S MITIGATION STRATEGIES:
MEASURE DD
■ A.Creek Restoration Projects, including restoration of creek
segments to improve water quality, hydrology, and wildlife
habitat to prevent floods, improve public accessibility and
increase community stewardship. Creeks may include:
– Sausal Creek; Lion Creek; Palo Seco Creek; Cinderella
Creek; Arroyo Viejo Creek; Shepard Creek; Glen Echo
Creek; Temescal Creek; Coliseum Slough; Horse Shoe
Creek; San Leandro Creek; Peralta Creek; Courtland
Creek
OAKLAND’S MITIGATION STRATEGIES
■ City of Oakland considering floating wetlands for
Lake Merritt as a pilot program
PROPOSED DESIGN STRATEGY
■ rain gardens located at the main culvert
outlets
■ phytoremediation floating pods connected to
subsurface aeration apparatus spread
throughout the lake
■ wetland/oyster reefs surrounding the shores
of the raingardens.
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THANK YOU!
REFERENCES
"NOAA Ocean Service Education." National Oceanic and Atmospheric Administration. NOAA, 2008. Web. 1 Nov. 2015.
"Center For Public Environmental Oversight." Center For Public Environmental Oversight. Web. 1 Nov. 2015.
"Why Plant for Clean Water." Why Plant for Clean Water. Rice Creek Watershed District. Web. 1 Nov. 2015.
WHITE PAPER ON WATER LEVEL CONTROL AND TIDAL FLOWS. Oakland: Lake Merritt Institute, 2002. Print.
"FAQ - Plants - Filtering Plants." Pond Plants. 2015. Web. 1 Nov. 2015.
Sonnenfeld, Josh. "After 143 Years, Oakland's Lake Merritt Reunites with the Bay - Save The Bay Blog." Save The Bay Blog. 17 Sept. 2012. Web. 1 Nov.
2015.
"The Lake Merritt Institute: Evaluations." The Lake Merritt Institute: Evaluations. Lake Merritt Institute. Web. 1 Nov. 2015.
Richards, Kathleen. "Improving Lake Merritt | East Bay Express." East Bay Express. 11 June 2014. Web. 1 Nov. 2015.
Mullins, Kathryn. "Lake Merritt: The Revival of Oakland's Jewel." SPUR. SPUR, 22 Jan. 2015. Web. 1 Nov. 2015.
Huang, Ai-vy Le, Victor Truisi, Darolyn Turner, Fred Yanez, Jin Feng Yu, Miguel Unigarro, Gail Vue, LaKisha Carduno, and Kevin Cuff. "Water Quality
Investigations at Lake Merritt in Oakland, California." UC Berkeley. Web. 1 Nov. 2015.
Upton, John. "Demolition Project Should Reduce Odor from Lake Merritt." The Bay Citizen. 14 June 2011. Web. 1 Nov. 2015.
Miller, Amy. "Polishing Oakland’s Crown Jewel: Lake Merritt Reborn." QUEST. 10 Aug. 2010. Web. 1 Nov. 2015.