Monthly Archives: February 2021

Do Wastewater Treatment Plants Remove Pharmaceuticals?

Wastewater treatment plants are there to clean and purify water that arrives through sewer lines, septage haulers, etc. The process removes bacteria, solids, and other impurities until the water is clean enough to go back into the district’s water supply or get released into area bodies of water.

What about pharmaceuticals? Can wastewater treatment plants remove pharmaceuticals before the water returns to public water sources, lakes, streams, and other water sources? Studies show that many drugs end up in treated water even after a normal treatment process.

Wastewater Treatment May Not Remove Everything

In a month’s time, it’s estimated that close to 46% of Americans have taken at least one prescription drug. As you get older, chronic health conditions are more likely. Around 85% of American’s aging adults (60 or older) take medications daily. Adults aren’t alone. It’s found that about 18% of children 12 or younger take at least one prescription medication.

You probably take vitamins, herbal remedies, over-the-counter meds, and/or prescriptions on a daily basis and never stop to think about the impact they have on wastewater. Pharmaceutical plants and the liquid manure from livestock treated with veterinary pharmaceuticals that gets spread on fields aren’t the only cause of these compounds getting into groundwater and streams.

The reality is that the medications people take also find their way into your wastewater. They’re excreted through fecal matter and urine or expired or unneeded pills are flushed down drains or toilets. The wastewater treatment process does what it can to remove them. The problem is that water treatment can’t get all of the drugs out of the water.

A study looked at the wastewater from 50 of the nation’s wastewater treatment plants. Pharmaceuticals were found in all 50 samples. Valsartan (blood pressure medication) had the highest levels, but atenolol (blood pressure), carbamazepine (epilepsy), and metoprolol (heart/beta-blocker) were also found in high levels. While it’s uncertain the levels remaining after the water is cleaned is dangerous to humans, questions arose as to whether the drugs would harm aquatic animals.

In 2020, a University of Cincinnati biologist decided to look at the effects of estrogen (birth control pills) on freshwater fish. As estrogen had been found in streams near wastewater treatment plants, the study looked to see what would happen if native fish were exposed.

In the study, the researchers focused on a native fish that has live births rather than lay eggs. They put them in fresh water that contained a controlled level of estrogen. The fishes’ fertility was affected and fewer babies, especially males, were born to the fish in the study. The shocking thing is that the researchers had used levels of estrogen that were 16 times lower than was found in the streams.

Many people today take antidepressants. How well is wastewater treatment removing antidepressants? Researchers took a look at the tissue of fish found upstream from two wastewater treatment plants in Colorado and Iowa. Fish found upstream showed no signs of antidepressants.

They also collected fish five miles downstream of where the same wastewater treatment plants were releasing treated water. Those fish had noticeable levels of common antidepressants like fluoxetine (Prozac) and sertraline (Xanax). The water samples also tested positive for containing those and bupropion (Wellbutrin), citalopram (Celexa), and venlafaxine (Effexor XR).

What about antibiotics? One of the first was penicillin, but science advanced and many of today’s antibiotics are synthetics like sulfonamides or semi-synthetics like amoxicillin. A study of water within the Great Lakes found that wastewater contained several pharmaceuticals including two antibiotics.

So many medications are being found in water that’s been treated and released to streams, rivers, lakes, and ponds. They’re making their way into the oceans. It’s shown that the drugs can impact fish, mammals, crustaceans, shellfish, and other aquatic creatures.

Federal Regulations on Wastewater Treatment Don’t Cover Pharmaceuticals

The Federal Government maintains a list of chemicals, metals, and other contaminants that must be removed from wastewater before it’s released. Pharmaceuticals are not on that list. While attention is being raised, only four compounds found in pharmaceuticals for human use are even being considered. Three of them are in birth control pills and one is an antibiotic.

This is concerning as a 2007 study tested for 17 different pharmaceuticals in samples taken from 20 different municipal water systems. More than 50% of the water samples tested positive for carbamazepine (anticonvulsant), ibuprofen (NSAID pain reliever), iopromide (contrast agent for scans of the body), meprobamate (tranquilizer), and phenytoin (anticonvulsant).

A second in-depth study went back and found meprobamate and phenytoin in 50% of the samples. While the levels were too low to impact humans, it does raise concerns on how these medications affect fish and other aquatic creatures.

Many wastewater treatment plants are already removing pharmaceuticals, but only a percentage is removed through typical wastewater treatment plans. There’s still a percentage making it into the water. Which leads to the question of what else can be done.

What Steps Help Remove Pharmaceuticals?

How well wastewater treatment removes pharmaceuticals depends on what system a district uses. Activated sludge is one of the more common treatment processes. It uses microorganisms to break down contaminants. It’s not overly effective on pharmaceuticals. Dr. Diana Aga, a chemistry professor, says more pharmaceuticals would be removed if wastewater treatment plants paired activated sludge with granular activated carbon filters.

What steps in water treatment help remove the medications people take? A study looked at the different water treatment steps and whether or not they were partly effective at removing certain medications.

  • Anabolics/Steroids – Reverse osmosis was most effective, but nanofiltration, ozonation, and granular activated carbon was also useful.
  • Antibiotics – Ultrafiltration with powdered activated carbon and reverse osmosis were effective.
  • Carbamazepine (Anticonvulsant) – Ultrafiltration with powdered activated carbon and reverse osmosis were the most effective treatment methods.
  • Diazepam (Sedative) – Reverse osmosis was the most effective with ultrafiltration using powdered activated carbon as a second-best choice.
  • Diclofenac and Ibuprofen (NSAID) – Reverse osmosis and soil aquifer treatments were the best options, and granular activated carbon filters also worked well on
  • Paracetamol (Tylenol) – Ozonation and reverse osmosis were the most effective ways to remove this pain reliever from wastewater.

There is a lot of evidence in filtration being the best way to remove pharmaceuticals. Your wastewater treatment plant can help get pharmaceuticals out of the wastewater that’s treated and released. What is your plant’s design? Have you set up a system that pairs activated sludge with some form of carbon filtration? Maybe it’s time to consider a change that helps keep pharmaceuticals out of the water while also improving your plant’s expenditures.

Is it time to upgrade your wastewater treatment equipment? If you’re looking to clean wastewater effectively and efficiently, modernizing some equipment can help improve your plant’s performance while lowering electricity costs. Your district saves money, which makes everyone happy.

Lakeside Equipment has been a leader in water purification for close to a century. Talk to us about our Learn more about the steps to take for cleaner water and lower energy costs.

Do Wastewater Treatment Plants Smell?

Stop and think about what wastewater treatment processes do. It’s not surprising that plants release noxious odors. The goal is to remove fecal matter, urine, and other waste products from the wastewater to make sure it’s clean before it’s released to lakes, ponds, rivers, or storage tanks where it’s reused by homes and businesses. The very nature of wastewater makes it a smelly venture.

While wastewater treatment plants do smell, it’s important to reduce those smells for several reasons. First, you don’t want people who live nearby to constantly complain to the town or city about the odors. Second, those odors are linked to harmful gases being released during the treatment process. Odor management helps protect the environment.

To best understand how to take care of problems with unpleasant odors, you have to look at each step of a wastewater treatment process. Figure out the best ways to reduce odors along the way.

The Steps to Wastewater Treatment

The exact steps to wastewater treatment depend on a plant’s design. Most follow these steps.

#1 – Screening: Wastewater that comes in from the sewer or is dropped off at a septage station is screened to remove things like plastic wrappers, tampon applicators, grease, rags, and other objects that could clog equipment.

#2 – Pumping: Once the wastewater is screened, it’s pumped to the next station for grit removal.

#3 – Grit Removal: Grit removal systems separate grit like sand where it sinks to the bottom of the vessel and is removed and trucked to landfills or compost piles.

#4 – Primary Settling: After grit is removed, the wastewater is moved to clarifiers where it sits so that sludge can settle at the bottom and grease floats to the top. Grease is skimmed away and joins the sludge in digesters. Some plants use chemicals to start removing phosphorus from the wastewater. The remaining water leaves the tank.

#5 – Aeration: The wastewater that remains is aerated so that microorganisms can start feeding on the pollutants.

#6 – Secondary Settling: As microorganisms finish their job, the wastewater goes to a secondary settling tank or lagoon and any remaining sludge goes to the bottom where it’s pumped out and goes back to aeration tanks.

#7 – Filtration: Wastewater is almost fully treated at this point. Any contaminants that remain are captured in the filtration materials. Filters are regularly rinsed out and that liquid goes back to the start of the wastewater treatment plant.

#8 – Disinfection: The final step in wastewater treatment involves the use of disinfection to kill remaining bacteria to 98% or higher. Ultraviolet disinfection is common and brings the now clean water to the levels needed to release it back to the environment or public water storage tanks. Before water goes back into rivers, ponds, and lakes, it may be aerated one more time to boost oxygen levels.

What Causes the Odor and How Do You Stop It?

Sewer and septic water smells anyway. As anaerobic digestion of the waste takes place, the organisms that break down the waste release certain gases like hydrogen sulfide and methane. These gases do not smell pleasant. Some liken it to the smell of a really rotten egg.

To understand what causes the foul odor, you need to understand what happens to the sludge removed during wastewater treatment. Here’s what happens to the sludge that’s removed from wastewater.

#1 – Sludge is separated and goes through anaerobic digestion. It’s heated to a certain temperature and uses anaerobic bacteria to break it down. In this process, hydrogen sulfide, carbon dioxide, and methane are produced and add to the smells found in a wastewater treatment plant.

#2 – Once the anaerobic digestion process ends, sludge is pumped from the digester onto a belt that allows water to drain. The water (filtrate) goes into tanks that will sit for several months before going to a site to be spread onto land. Remaining solids go to a facility where it’s composted and sometimes used to fertilize the soil.

If an anaerobic digester is sealed off with a cover or similar enclosure, the smell can’t go far. If the digestion tanks are open, that smell will permeate the air. The smell can travel, so people who live nearby may complain. It’s not too different from the way a farm that spreads liquid manure on fields ends up making an entire neighborhood smell of the manure. It’s important, but people do not like it. You may also know the foul odors that come from a manhole when you walk past on a hot summer’s day.

The odors can seem worse on some days over others. On a windy day, neighbors may notice the smell more. On a hot, humid day, the smell will likely seem worse.

Your first goal is to find where the odors are worse and address those issues. Consult with a wastewater treatment expert if you’re having problems narrowing it down. Sometimes, equipment upgrades and the installation of biofilters or carbon filters within ductwork systems can help reduce odors. Deodorizing systems can also help.

Be aware that masking the odor won’t stop it. You’re still going to find the odor leads to complaints from time to time. It’s most likely that you’ll hear the bulk of the complaints in the spring and summer when people want to open their windows and let fresh air into the home.

Benefits to Covering Your Wastewater Lagoons and Tanks and Other Equipment

Start with the screw pumps you use to move wastewater from plant lift stations or to return sludge from clarifiers back to aeration tanks. Open screw pumps will allow odors to escape. You should consider if enclosed screw pumps are better for your odor reduction goals.

If you put a cover over the open tanks and lagoons at your wastewater treatment plant, there’s a second benefit to consider. You could trap the gas that’s released and use it for biogas. That biogas can lower your plant’s heating costs by using it to fuel your heating system. You gain twice the benefits as you slash your heating bills and eliminate odors that may have locals complaining.

When you cover your open tanks and lagoons, there’s a second benefit. Less water is lost to evaporation. This reduces the quantity of chemicals your plant needs to use in the wastewater treatment process. You’ll save money on the cost of chemicals, too.

Covers are a smart investment, but they’re not a one-size-fits-all solution. Covers may be made of metals like aluminum or steel or fiberglass. Some float on the surface, some are retractable, and some are flexible and made from geomembranes. They have to be airtight and designed to stand up to your area’s weather. You need to be able to remove them in a timely manner for testing, repairs, and emergencies. To know which best fits your needs, you need to talk to an expert in wastewater treatment plant design and installation.

Is it time to upgrade your wastewater treatment plant? Are you looking at making changes that help lower energy costs and make the people in your district happier with your dedication to quality and costs at the same? Contact our experts for advice. Lakeside Equipment has been in the wastewater treatment industry for close to 100 years. We’ll assure you achieve your goals.