single sample maximum (for the sampling event) is determined by calculating the geometric mean of the five samples taken on the given day. If it exceeds 235, an advisory is posted. The second cut off is the 30-day geometric mean of 126. This is determined by calculating the geometric mean of all samples taken over a 30 day period of time. If this exceeds 126, then an advisory is posted. Advisories are posted by using the data gathered by sampling with consideration of other factors that may have impacted sampling results and any events that are known to have occurred (sewage overflow, heavy rain fall, natural disaster).
Closures of beaches only happen when there is an imminent risk to public health and may include a documented sewage overflow (contaminant) or other public health or safety issue.
LPC Report to the POACRE July 2014 All Member Meeting
Lakes Preservation Committee
Chair – Dr. Andy Rogers
• POACRE All Member Meeting
• July 2014
Volunteers do not
necessarily have the
time; they just have
the heart. Elizabeth
Goals for Lake Lariat:
– Safe -
– Pleasing To Look At -
– Free From Unpleasant Odors -
– Good For Fishing -
– Good For Boating -
– Swimmable -
What the LPC Does
– Monitor Lake Lariat.
– Study the literature.
– Interview experts in government, indusry and
– When we get new information, we review it carefully.
– Look for environmentally sound solutions
– Implement solutions.
– Not looking for quick fixes or expensive, hard to maintain
– Address member concerns
– Working with POACRE administration to bring in
– Foundation for Community Partnerships
• DNR study (2009) shows lack of cover for fish
development in Lake Lariat. This includes
downed trees and wetland/aquatic plants.
• Solution: We installed artificial cover in 2011
• Floating islands provide cover as well.
• Fisheries expert Dave Beasley recommended
encouraging fishermen to take home what
they legally catch to improve the fishery.
• Trophy Bass Management was implemented
in Lake Lariat in 1991.
• Trophy Bass Management allows anglers to
keep five Largemouth Bass per day.
• All bass between 11 and 15 inches in length
must be released. One bass, greater than 15
inches in length, may be kept as part of the 5
• MDE recommended removing the larger bass
that are more highly contaminated with
• DNR does not recommend this strategy based
on the Trophy Bass Management.
• Has Trophy Bass Management for 23 years
improved the fishery?
• Corbicula clams
• Two have been reported caught on CRE property.
• If you catch one, kill it, then report it to the Md.
Department of Natural Resources.
• If you catch it in or near CRE, please report it to the
• There is no evidence of any in Lake Lariat.
• They are reported to be “Delicious”.
Corbicula (Asian) clams
• Twenty or so were found at Lake Lariat Beach
• According to DNR they could have been
introduced to the lake by several means.
•No known way to remove them.
•You can harvest them but it requires a
permit to stock them in a pond or lake.
•They are known for being a delicacy,
however, DNR advised against
harvesting them out of the lake.
Durango Trail Access to
Lake Lariat Water Quality
• Blue green algae
• E. Coli
Blue Green Algae
No blooms have been
reported on Lake Lariat
for several years
although other ponds
are infested with it.
• Lake Lariat is considered impaired
because it is not safe to eat a constant
diet of large mouth bass (no more than 10
8-ounce servings per year.) and other fish
from the lake.
• US EPA safe drinking water level for
mercury is 1000 times higher than the
mercury level in Lake Lariat water.
Calvert County Testing Results for E. Coli
2003 – 2014
• Average E. Coli rating based on the geometric mean of 5 samples taken the same day on the Lake
• If geometric mean exceeds 235 cells/ml, Calvert County issues an advisory
• If the 30-day geometric mean exceeds 126 ml, Calvert County issues an advisory.
• For advisories go to:
Causes of E. Coli
• Failing septic systems
• Stormwater carrying pet waste
• Wild animals
Major rain events can
wash a fair amount of
animal waste into any
nearby bodies of
Do NOT put Hydrilla in our lake.
•It can become so dense that swimmers and
motorboats cannot pass.
•It can harbor blue green algae leading to the death
of birds including bald eagles.
•It can grow in 20 feet of water.
If you think you have a great idea for how to fix the
lake, please come to the LPC. We are in
communication with experts.
What you can do.
Reduce nutrient inputs to the lake
Reduce fertilizer use
Fix your septic system
Encourage proper stormwater management
We need a secretary
Contact CRE office or use CRE webpage
Unofficial Facebook Page: