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WaterOperator.org Blog

Articles in support of small community water and wastewater operators.

Featured Video: Wastewater Treatment -Troubleshooting Aeration Basin

Featured Video: Wastewater Treatment -Troubleshooting Aeration Basin

This week’s blog features a wastewater troubleshooting video by the YouTube account Wastewater Operations Channel. The account is run by Jon Kercher, an operator of 10 years who uploads educational videos filmed during the work day at his wastewater treatment plant.

In this video, Jon demonstrates how to troubleshoot a disparity between two air legs within an aeration basin that should be equal flow. The problem was noticed when the basin was put into lead position. This video not only demonstrates how to troubleshoot a flow disparity, but teaches a great methodology for troubleshooting any wastewater treatment issues. Jon notes that while we have a general tendency to gravitate our troubleshooting toward process parameters, we must also consider monitoring parameters as well. Watch his video to find out what was causing the flow disparity!

Nocardia Foam in Activated Sludge Systems

Nocardia Foam in Activated Sludge Systems

Nocardioforms are filamentous, Gram positive actinomycete bacteria that can cause persistent and excessive foaming in activated sludge plants during the summertime. There are nine main genus of nocardioforms. Two of these genera are involved in activated sludge foaming, Rhodococcus and Nocardia with the latter being the better known troublemaker. How to best control Nocardia foam is a highly debated topic.

Nocardioforms are known for their branch-like hyphae that extend from the cell wall similar to the hyphae found in fungi. These branches link together with other filaments and floc. Simple and complex organic material make up their diet which includes fats, oils, and grease (FOG). Nocardioforms are slow growing and utilize the aerobic conditions established by an aeration tank. These actinomycetes generally have difficulty out-competing other wastewater microorganisms, but once established they're a handful to remove.

Present in lower concentrations, Nocardia help to stabilize floc structure. The bacteria can rapidly breakdown biochemical oxygen demand (BOD) which can be beneficial to high strength wastewater. In higher concentrations, Nocardia can rip the floc apart and swiftly breakdown BOD starving out floc forming bacteria. The dense, brown foam that accompanies an outbreak forms when filaments float to the surface as a result of their low-density fatty acid membrane and the waxy, hydrophobic biosurfactant that coats their bodies. Bubbles from the aeration system can also help the filaments to float. Unlike Microthrix, nocardioforms are not often associated with sludge bulking.

Unfortunately, the conditions required for a nocardioform outbreak are still debated. In general, any change in temperature, pH, dissolved oxygen (DO), solids concentration, or nutrients might spur an outbreak. It’s believed that nocardioforms will be most favored under warm temperatures with a high concentration of FOG, low food to mass (F/M) ratio, and/or a high mean cell residence time (MCRT). Since nocardioforms grow slowly, they need ample time to proliferate, and under low F/M their larger surface area helps to secure nutrients easily. Some people theorize that anaerobic conditions in parts of the aeration tank or surfactants can encourage Nocardia growth as well.

Before deciding on a treatment solution, it helps to confirm that you are dealing with nocardioforms and not some other filament. Just because your foam is brown, doesn’t ensure that Nocardia is the culprit. Toni Glymph has developed a manual that describes how to identify filaments under the microscope. Nocardia is both Gram positive and Neisser positive, but after reading his guide you’ll find that only a Gram stain is really required for identification.

Treatment solutions for nocardioform foam are also highly debated. Using a high volume water spray will temporarily break down the foam, but be prepared for its return. A better solution is to skim off excess foam so the bacteria is not recycled back into the system. Chlorination is not highly recommended. The branching Nocardia filaments prevent sufficient disinfectant contact while healthy floc bacteria are killed. Many companies promote defoaming products, but the interlocking filaments are often too stable for these chemicals as well. Most resources recommend reducing your MCRT to under 8 days while increasing (F/M). Wastewater technician, Jeff Crowther, lists three of his own treatment recommendations on page 10 of the H2Oregon Springs 2016 Newsletter. Solids wasting may be the most common control method. Operators should learn about the life cycle of Nocardia to maintain a system that avoids future foaming incidents.

Featured Video: Replacing the Power Cord on a Sewage Pump

Featured Video: Replacing the Power Cord on a Sewage Pump

Submersible sewage pumps can be used for a variety of applications spanning the needs of residential homes to wastewater treatment plants depending on their size and design. A submersible pump is made up of a submerged motor filled with air or oil. Various impellers designs determine what sized solids the pump can handle.

In this week’s featured video, Chris with R.C. Worst & Co. demonstrates how to replace the power cord on a submersible sewage pump. This particular pump is designed for septic tanks and the sewage handling of commercial and residential applications. While working on the pump, he offers some tips and tricks that can help you to save money during repairs and prevent additional damage. As a bonus he discovers some unexpected factory damage and demonstrates how to repair broken wiring. If you need to fix a pump from your own system, remember that this sort of repair work should only be made by operators with the appropriate training. You can find hands-on pump training in your area by visiting our operator event calendar.

Preventing a Bloodworm Invasion

Preventing a Bloodworm Invasion

Midge fly infestations can pose considerable challenges for activated sludge systems and lagoons. Also known as Chironomids or bloodworms in their larvae stage, these insects resemble mosquitos without the blood sucking proboscis. Adult males can be distinguished from females based on their feather like antennae. After dormancy in the winter, midge flies emerge in the summer ready to lay between 100 and 3,000 eggs per female.

Though midge flies do not suck blood like mosquitos, they disrupt communities in other ways. Swarms annoy both local residents and operators by flying into unsuspecting mouths and flooding outdoor lighting. A study by Selden et al. (2013) found that wastewater operators can develop allergic reactions from midge fly exposure. Chironomids can also cause quite a startle to the public when bright red larvae make their way into drinking water systems.

When it comes to maintaining treatment systems, wastewater operators may be most concerned with the larvae stage of midge flies. Their sticky red bodies cling to suspended solids encasing them in a cocoon of decaying organic matter. Under the protection of these cocoons, they can consume considerable amounts of sludge, bacteria flocc, and nitrifying bacteria. An infestation will cause sludge clumping, rising solids, or foaming issues. In one small town a bloodworm invasion wreaked havoc on an activated sludge plant over a single weekend. The wastewater operator found sticky clumps of eggs had congested the system’s pumps while larvae had eaten away at his mixed liquor suspended solids (MLSS).

Facultative lagoons and secondary clarifiers are a favored breeding ground for these pests. Midge flies prefer to lay their eggs in still, high-nutrient water with fixed media, floating scum, or algae. Once the eggs hatch, larvae will likely sink to the bottom to feed on organic matter and sludge. The hemoglobin that gives bloodworms their red color also allows them to live in low dissolved oxygen (DO) conditions.

To avoid bloodworm infestations, operators should focus on encouraging circulation and limiting food sources. Systems can start midge fly control with mixing, limiting surface scum and algae, installing bug zappers, attracting bats and swallows, or turning off lights at night. Introducing a predatory fish can also help. Lagoon operators can encourage circulation by cutting back overgrown vegetation. Any dead spots in circulation should be addressed. When these methods don’t work, some systems will use larvicides and chemical agents as a last resort. Operators should check that the control methods they’ve selected are approved by their local regulatory authorities before use.

When summer starts make sure your treatment system is kept clean and free of obstructions to circulation. With good preventative maintenance, you can spare yourself the nightmares of a bloodworm invasion.

A Microscopic Look at the Role and Life Cycle of Daphnia in Wastewater Lagoons

A Microscopic Look at the Role and Life Cycle of Daphnia in Wastewater Lagoons

Knowledge of lagoon microbiology can provide proactive insight into the present conditions of your wastewater treatment processes. Since we have already covered general wastewater microbiology in a previous featured video, this week’s blog post will highlight the specific roles of Daphnia in wastewater digestion.

Daphnia, also known as water fleas and Ceriodaphnia, are metazoan crustaceans that maintain a useful position in the wastewater digestion food chain if controlled by a limiting food source or the careful addition of hyacinths. These one-eyed crustaceans can consume yeast, algae, bacteria, protozoa and occasionally sludge during the winter. In the wild Daphnia are a food source for small fish, tad poles, and aquatic insects. General stressors for water fleas include cold temperatures, overcrowding, low dissolved oxygen (DO), high ammonia levels, and high pH.

To provide context for Daphnia's role in lagoon treatment requires a review of the wastewater food chain. Bacteria are at the heart of waste digestion breaking down organic material into settleable particles. Protozoa feed on these bacteria populations reducing the organic load. Metazoan organisms like Daphnia keep the populations of protozoa, bacteria, and algae in check.

Daphnia can be useful to wastewater operators under healthy lagoon conditions. These water fleas control green algae populations in the summer. As long as cyanobacteria weren't competing with those algae populations, overall pond health will improve by a reduction in total suspended solids (TSS), cloudiness, and turbidity. At the cost of growing Daphnia populations, dissolved oxygen levels decrease.

Water fleas are often indicators for low dissolved oxygen and water toxicity. Under low DO, Daphnia produce hemoglobin to increase oxygen efficiency. This hemoglobin turns water fleas reddish-pink causing red streaks to appear in your lagoon. When operators see red water fleas, they should consider treating the lagoon with aeration or mixing. Given their low tolerance to toxicity and short generational cycles, Daphnia are also used in the EPA's whole effluent toxicity tests (WET).

Now that we have a better understanding of water fleas, we can appreciate this microscopic view of Daphnia as told by Sacramento Splash. The video reviews the natural life cycle and anatomy of these helpful water crustaceans.

Featured Video: Flushable Wipe's Effects on Our Sewer System

Featured Video: Flushable Wipe's Effects on Our Sewer System

Many collection systems struggle to prevent the costly and time consuming repairs associated with flushable wipes. Despite the label these wipes remain intact in sewer systems. They often clump into large blockages held together by grease. When the blockage becomes too large, sewers experience sanitary backups and pricey pump damage. 

This week’s featured video reviews the management options for flushable wipes as explained by Great Lakes Water Authority. One common solution for wipe buildup requires the installation of sewer grates and filter screens. Though operators will be required to regularly clear away wipe accumulation, systems can plan for the added maintenance expenses while preventing unexpected downtime. Other systems may choose to break down wipes with chopper pumps or grinder pumps, however this can lead to reweaving later in the collection system.

The video ultimately demonstrates that there is no single and efficient method to avoid wipe backups other than consumer education. With the final costs of wipe maintenance funded by the rate-payer, collection systems should be vocal in educating their customers about the products that can and cannot be flushed down the toilet. For more information on flushable products, check out our blog post Will it Flush.

Featured Video: Smelly Lagoon? Diagnosing and Correcting Lagoon Odors

Featured Video: Smelly Lagoon? Diagnosing and Correcting Lagoon Odors

As weather begins warming up for spring, many lagoons system owners have to manage odor issues and water turnover. In this week’s featured video, an experienced “Lagoon-atic” describes what causes lagoon odors and the best practices to manage them.

The most dreaded odors from lagoons systems are caused by sulfur dioxide and hydrogen sulfide gases. These gases emit a rotten egg odor that often leads to complaints from locals in the area. Under oxygen-stressed conditions, insufficient dissolved oxygen (DO) levels favor anaerobic digestion of biological oxygen demand (BOD) and sludge by sulfur bacteria.

There are many causes for low DO in lagoon systems including overloading, sludge build up, and lagoon turnover during season changes. The video suggests solutions for low DO reviewing aeration, baffles, bioaugmentation, and lagoon covers. When aeration is not financially practical, using a pump to recirculate the water can resolve most odor issues caused by sulfur bacteria.


This video also discusses the earthy smell of a healthy lagoon and other odor causing problems a lagoon may experience. Grassy odors indicate high levels of algae favored by warming temperatures, long detention times, excess sunlight, and excess nutrients. As spring approaches the solubilization of solids from the sludge blanket can cause nutrient release. This issue can be corrected by a reduction in the sludge blanket. Fishy odors may result from cyanobacteria growth under conditions with warm temperatures, high nutrient levels, thermal stratification, and still water. The longer water remains still, potential for cyanobacteria growth increases. Cyanobacteria can be reduced with chemical control, aeration, circulation, and ultrasonic waves. 

Spring time has potential to pose many odor issues for lagoon systems. Operators can maintain a healthy lagoon by ensuring sufficient DO levels, controlling sludge buildup, and mixing.

Featured Video: The Future of Water

Featured Video: The Future of Water

Water is a scarce resource for many communities around the globe, and this scarcity is becoming more and more widespread. Our featured video this week from Quartz Media looks out how one locality half a world away has addressed this challenge, and how the rest of us can learn from systems like these where the "future of water" has already arrived.

While this video focuses on a larger metropolitan area, there are some interesting takeaways for smaller systems as well such as:

  •  Solutions to water challenges are best solved at the individual and/or community level. 
  •  Water reuse is most likely already happening in your community and efforts can be made to change public perceptions. For example, a wastewater pipe enters the Mississippi River every 8 miles - meaning almost every community using the river as a water source is already drinking someone else's wastewater!     

Spooky Sewers and Things That Go Bump at the Treatment Plant: 2018 Edition

Spooky Sewers and Things That Go Bump at the Treatment Plant: 2018 Edition
An October chill is in the air and darkness is falling earlier and earlier. It must be time to share our annual bone-chilling list of some of the wierdest, wackiest and downright most frightening water operator stories we came across this year (check out last year's list here)!
 

First, can you imagine what it would be like to get sucked through a sewer for over a mile? Well, it happened to this man when his safety harness came undone back in 2010. And although he survives, the crappy experience is surely something he will never forget. 

While we are talking collections O&M, here's a video describing one characteristic of a successful wastewater operator: a strong stomach. Another characteristic? Knowing not to "fling this on your partner."  And believe me, you don't want to know what "this" is!

Sometimes, though, what flows into a sewer simply doesn't come out, no matter how much you work on it. That is when you call in the professionals: sewer divers.

This is exactly what the water system in Charleston, SC did when they could not clear an obstruction earlier this month. They sent specialized sewer divers 80-90 feet deep into raw sewage in complete darkness to search for the obstruction with their hands..

What did they find? You guessed it: a large mass of "flushable" wipes. Lucky for us, the water system documented the whole episode on social media, but respectfully shot the pictures in low-res for our benefit.

If you want to dive deeper into the topic of sewer exploration, we double dare you to watch this video about a man who swims through Mexico City's wastewater system on a regular basis to keep it working. 

Other types of obstructions have to be dealt with in other ways. This past summer, utility workers spotted an alligator swimming in the Mineral Springs, PA wastewater treatment plant. A private contractor hired by the state Fish and Boat Commission had to use dead animals as bait to try and snag the gator with a fishing hook. 

You have to admit, wastewater often gets a bad wrap. To prove this, just ask any operator from Baltimore's wastewater treatment plant what happened there back in 2009. That was the year they had to call in experts to deal with a 4-acre spider web that had coated the plant. According to a scientific paper that appeared in American Entomologist, the “silk lay piled on the floor in rope-like clumps as thick as a fire hose” where plant employees had swept aside the webbing to access equipment. Scientists estimate the megaweb contained about 107 million spiders

Finally, it wouldn't be Halloween without ghosts, or ghost water, to be more precise. What is ghost water you ask? Well, pervasive leaks and long repair delays are causing water to disappear in Kansas City, Missouri (a kind of haunting experienced by water systems all across the country it seems). According to this 2017 article, nobody knows exactly where the water is going, but the water department points to faulty meters, theft, aging pipes and abandoned houses. Spooky!


Featured Videos: Small Communities Benefit From Shared Resources

Featured Videos: Small Communities Benefit From Shared Resources

The Small Communities Environmental Infrastructure Group assists small Ohio communities in finding resources to help solve their infrastructure and funding problems. These two videos feature water and sewer district officials and staff discussing the benefits of participating in SCEIG regional partnerships in order to better serve their communities.