May 22, 2019

Protecting Your Pumps & Piping From Zebra Mussels

by Jeff McHattie

WHAT ARE ZEBRA MUSSELS AND HOW CAN YOU PROTECT YOUR PUMPS AND PIPING FROM THEM?

Zebra Mussels (Dreissena polymorpha) are a small shellfish found in freshwater. They are easily identified by their size, shape and coloring. These shellfish are about the size of a fingernail, are shaped like a letter "D" and get their name from their zebra-like stripes.

Zebra Mussels are known for their ability to adhere to hard surfaces and negatively impact aquatic life, clog water pipes/pumps, foul the odor and taste of water and damage boats. Once the Zebra Mussel establishes itself in a body of water, there is really no way of removing them. A single Zebra Mussel can create over a million larvae per year and they can survive for a week outside of water.

We hear more and more about this phenomenon as they continue to spread to new bodies of water across Texas and the rest of the United States. It is believed that these shellfish originated in the Caspian and Black Seas south of Russia and the Ukraine, eventually making their way to the Great Lakes in the late 80's via the hulls of commercial ships.

Today the Zebra Mussels have spread to more than half of the United States first appearing in Texas in 2009. Now in 2019 it is very common to see pumps come in for repair covered in Zebra Mussels.

Follow the link below to the Texas Parks & Wildlife website where you can find frequently asked questions in regards to the Zebra Mussels and how to maintain your boats to help stop their spread. They have also provided a detailed map indicating what bodies of water have confirmed infestations.

https://tpwd.texas.gov/publications/pwdpubs/media/pwd_lf_t3200_1965_zebra_mussel_faq.pdf

In addition to the Zebra Mussel there is also the Quagga Mussel which dominates inhabitance in the Great Lakes due to their better adaptation to living in colder temperature.

These mussels are a real nuisance when it comes to pumping and moving water. From the image above you can see their effect on the flow ways of this pipe.

A lot of money goes into the service and maintenance to reverse the damage and effects these mussels have on pumps. We at Smith Pump Company are capable and available to assist with your service and repair needs but above all we want to provide the appropriate guidance and direction when something like this can be easily avoided.

So just how do we combat this problem?

The answer lies within the materials themselves. It is found that marine organisms can attach to some metals and alloys more easily than others. Steel, Aluminum and Titanium are subjective to easy fouling but Copper-based alloys are not!

Copper has been used for many years to protect boat hulls from this very same problem. When copper corrodes, a layer of cuprous oxide is formed. This layer, while relatively harmless to humans, is toxic to the mussels.

You may ask, how do you prevent leaching into the water? In comes, 90/10 Copper Nickel Alloy, an excellent alternative to copper that can prevent bio-fouling in freshwater without the issue of leaching.

The below images are of intake screens located at Smith Pump Company's Waco facility. They are fully fabricated in 90/10 Copper Nickel Alloy. They measure 36" in diameter and 130" in length with a capacity of 11,800 GPM at 0.5 ft/s per screen. These will mount to large water intake structures. The anti-fouling properties of the Copper Nickel Alloy will help keep these screens clear so that the pumps are not affected by the restriction in flow.

Copper Nickel coating applied through a thermal spray process is also available as an alternative solution. This is typically applied to a stainless steel surface and can be stronger, lighter and more cost-effective. Smith Pump Company custom designed vortex suppressors are a good example of something this could be a consideration for.