Potential Zebra and Quagga Mussels Impacts in Standley Lake Zebra - - PowerPoint PPT Presentation

Potential Zebra and Quagga Mussels Impacts in Standley Lake

Zebra (Dreissena polymorpha) and Quagga (Dreissena rostiformis bugensis) Mussels

• Both are an aquatic invasive species (non-

native)

• Very similar in impacts on water bodies
• Grow to approximately 1 inch (Zebra

mussels somewhat smaller)

• The only freshwater mollusk species that

attach via threads to hard surfaces

Background

• Originate from eastern Europe (Caspian

& Black Sea)

Zebra/Quagga Mussel Biology

• Spawn one to two times

per year in Great Lake

• Each female can produce

1 million eggs per year

• Seeing 3 times that in

warmer Lake Mead

• Filter one quart of water

per day/mussel

Beer Can

Biology

• Fertilized eggs develop

within a few days into free- swimming larvae called veligers

• Settle onto hard surfaces

and quickly attach with very strong bond

• As dense as 700,000 per

square meter

2008

2015

Impacts of Zebra Mussels

Lake Winnebago, Wisconsin

Standley Lake as a Water Supply

Infrastructure Impacts…

• Mussel attachment could interrupt basic

water service

• Some facilities have reported large

reductions in pumping capacity and

• ccasional shutdowns
• They can move through pipelines and

infest water treatment plant processes and equipment

Sampling Plates at Parker Dam, California after only six weeks

Impacts to Water Treatment Plant Infrastructure

Pipe clogged with Zebra Mussels

Standley Lake Outlet Structure

(being lowered into lake during 2003 rehabilitation project)

Underwater Photo – Domestic Water Intake Parker Dam (CA) - February 21, 2008

Underwater Photo – Trash Rack Parker Dam (CA)- January 15, 2008

Standley Lake Outlet System

Semper WTF Northwest WTF Thornton WTF FRICO Release

Standley Lake

Northglenn WTF SL Dam

WTF = Water Treatment Facility = a Valve

Potential Costs to the City

• Quagga/Zebra Mussel Risk Assessment

and Treatment Study

– HDR, 2010

• $8.26 Million Capital Costs
• $2.5 Million Operations and Maintenance

– 2009 $

Impacts on Lake Ecosystem

• Filtering so much water makes it clearer
• Clear water allows light to penetrate

further

• More light penetration to greater depths

allows plants and algae to grow deeper than before

Further impacts

• This also results in more bad algae, which

create taste and odor problems. These are difficult and expensive to treat

• Decomposing algae mats stink
• Harbor e. coli and botulism

– Hundreds of thousands of bird deaths in the Great Lakes

Zebra Mussel on Crayfish

Impacts to Boats

Recreation Impacts:

• Rotting mussels and

sharp shells on shorelines

• Smelly algae blooms
• Downstream impacts
• n Big Dry Creek and

rivers and reservoirs downstream