How Can You Prevent Overflow Situations When It Floods?

During Hurricane Ian, upwards of 20 inches of rain fell in southwestern Florida. Bradenton is one of many water treatment plants that had no choice but to release millions of gallons of wastewater into a nearby river. A spill of 7.2 million gallons of sewer water leaked into the Indian River Lagoon. Miami saw thousands of gallons of sewage overflow into storm drains. These are just two of a long list of issues, and it’s not a problem Florida officials are seeing for the first time.

During two hurricanes in 2016, 250 million gallons of raw sewage spilled into the environment. Millions of gallons leaked during Hurricane Irma in 2017. One area that saw no issues was the Florida Keys, where $1 billion in upgrades led to sealed pipes and an advanced wastewater treatment system that removes nitrogen and releases the treated water over 3,000 feet below sea level.

Florida isn’t the only state experiencing raw sewage spills during flooding rains. Back in January, 8.5 million gallons of sewage spilled into a Los Angeles waterway. Wisconsin Rapids saw about 165,000 gallons overflow into the Wisconsin River.

These sewage spills are public health hazards. The raw sewage is rife with pathogens like E. coli, campylobacter, and salmonella. Nitrogen in the waste can lead to algae blooms in the rivers, lakes, and oceans.  When there are flooding rains, overflow situations are possible. How can you prevent them?

What Is Your Current Set-Up?

Combined sewer overflow is a system where stormwater runoff, sewage, and industrial wastewater all flow in one pipe to one wastewater treatment plant. If stormwater runoff increases in heavy rainfall or snowmelt, the excess water can become a problem for the treatment plant. Suddenly, there’s more water coming in than the equipment can handle and the plant has to release untreated wastewater to the lake or river.

Many cities and districts have moved away from this system, but approximately 700 of these systems still exist according to the EPA. They’re all bound to the 1994 CSO Control Policy and the Clean Water Act. If you’re in a district where this is the design, it’s time to consider a change.

Sanitary sewer systems are more common. Sewer and industrial wastewater travel to the wastewater treatment plant while storm runoff travels to storm drains and out to bodies of water from there. Storm runoff isn’t treated, so it’s important that area residents don’t pour chemicals down storm drains. 

Introducing the Integrated Planning Elements

A few years ago, Congress enacted the Water Infrastructure Improvement Act. The idea was to offer ways for districts to voluntarily begin to make changes in stormwater and wastewater planning in order to meet standards set forth in the Clean Water Act. There are six elements to the framework of the Water Infrastructure Improvement Act.

  1. Brainstorm and plan out the requirements and drivers.
  2. Map out the existing infrastructure in a municipality’s stormwater and wastewater systems.
  3. Connect with project stakeholders.
  4. Brainstorm, evaluate, and select alternative plans.
  5. Analyze the performance.
  6. Formally adopt the necessary changes.

Just over two dozen districts started to integrate measures or developed and completed their changes. As more money is being earmarked for infrastructure improvements, it’s time to look at the steps your wastewater and stormwater district can take to lower the chances of a sewage spill during flooding.

Look at Your Capacity and Add Flood-Proofing Measures

Stop and look at the current capacity of your wastewater treatment facility. If heavy rainfall is causing system overflows, it’s time to look at upgrades, repairs, and adding to the existing capacity. Not only can that increased capacity help in times of heavy rain, but it also helps with population growth in the years to come.

In addition, if your facility is in a low-lying area, it’s time to look at flood-proofing measures that help protect tanks, ponds, and other equipment. Flood barriers are ideal for keeping flood water away, and servers and network hubs need to be on higher ground. Submersible pumps will help protect your equipment. Use the EPA’s flood planning guide to determine if you could be impacted by a 100-year flood and get helpful tips on where you should focus your upgrades and changes.

Upgrade Your Older Equipment 

If you have older wastewater treatment equipment, it’s time to address the benefits of upgrading to newer, more efficient waterproof or submersible pumps and motors. Ideally, look for equipment that has adjustable motors that will work harder when flow rates increase and slow down when it decreases.

An addition of a bar screen may be enough to help with combined sewer overflows. If back-ups occur regularly as trash, sticks, branches, leaves, and other materials build up on screens, it’s time to look at better screening. With trash and other debris cleared and moved to a landfill, it allows water to flow correctly, which prevents overflows and costly fines.

If you don’t already have Supervisory Control and Data Acquisition (SCADA) technology, you need it. Computers can monitor how well the system is working and identify problems before they start. With flowmeters, facility personnel can spot overflows, chemical imbalances, and leaks and take immediate action. 

Plus, SCADA can help you automate your facility. You’ll still need operators, but you’ll have 24/7 monitoring to avoid overflows. Being able to analyze real-time data and get timely alerts is important when it comes to flood management and avoidance of fines and EPA violations.

Careful City Design Is Equally Important

A stormwater system and wastewater treatment plan should make upgrades to help prevent overflow situations, but it also helps if city planners look at environmentally-friendly changes that help with rainwater. 

Permeable surfaces are key to this process. Instead of paved roads, concrete sidewalks, and other impermeable structures that allow water to collect and flow like a river, add green areas where the water can soak in. Rain gardens, porous paving materials, and green roofs also help. 

Bioswales are also gaining popularity. These sunken areas along roads are filled with greenery and piping that helps complete the primary filtering before distributing the water that’s in excess of what the plants use.

Instead of building right on river banks, setting buildings farther away to allow for the rise of water in a floodplain is also important. 

Get Expert Advice from Lakeside Equipment

Work with an expert in water treatment designs, repairs, and installations. It’s important that your system be carefully designed to meet your growing community’s needs and changing weather patterns. Every measure you take to prepare your facility for flooding or heavy rain is important.

Lakeside Equipment specializes in water treatment and has been in business for nearly a century. Talk to us about your current treatment plant’s equipment and where you feel it’s falling short. We’ll help you design a cost-effective system that’s prepared for floods and population growth.