While storage tank overfills are certainly not new to the chemical industry, overspills and leaks are happening on a frequent basis and don’t seem to be slowing down anytime soon. Year after year, thousands of spills are reported to EPA. With thousands of overfills reported each year, this translates into a lot of damage that’s occurring to your employees’ safety, the environment and your budget.
So, in the age of information and new technology, why are overfills still happening?
There are many reasons why overfills occur; however, two of the most common explanations for overfills are inaccurate technology and cutting corners.
When your operating system is running smoothly and the chance of an overspill is slim, facilities tend to cut corners. It’s easy to do so, especially when you have to manage budget cuts and personnel loss; however, that’s when you need to be on your toes and making sure that everything is up-to-date and that you have all of your necessary precautions and instruments in place.
Storage tanks should have two measurement points to ensure the best possible protection, a continuous level monitoring device and a point level switch. The continuous level device will provide the necessary information for controlling the level in the tank while the point level switch will provide the backup reassurance.
In some cases, facilities use alarms and trips, which are supposed to act as back-up layers, as the only layer of protection. While your point level switch may not be used for years, this is still a critical protection point since there’s no other layer of protection between the tank and an overspill. In other instances, facilities have deliberately filled their tanks above normal operating levels to make the start-up process easier. Overfilling your tank can quickly lead to potential issues since this method removes any possible monitoring applications that you can use to control the tank levels.
Okay, so now that we’ve identified why overfills are happening, how can I avoid them?
The best ways to protect your facility from overfills are:
• Monitoring your tanks to make sure that they are not leaking.
• Monitoring and checking your instruments’ accuracy.
• Providing a secondary bin so that if your tank does overflow, it can overflow into another container instead of impacting the environment and water supply.
• Emphasize the importance of risk assessments and make sure that they are carried out.
What happens if I do all of that and my system is still experiencing overfills?
Remember, your instrumentation exists to provide information on the level in the tank and monitor the level content and alarm you in the event that the level exceeds recommendations and /or has reached a critical level that could lead to an overspill. If overspills are still occurring then you will need to re-evaluate the automation and control system and its configuration.
Do you have the right instruments installed?
Stay tuned for the second installment on this topic. I will address the safety aspect of overfill protection and how you can protect your workers.