After a long winter or summer, seasonal changes can be pleasant. However, one side effect of changing temperatures is the undesirable effect produced in wastewater systems, particularly lagoon systems. During the fall and spring months, wastewater lagoons often experience turnover due to changing temperatures. During the fall, cold air decreases the temperature in the upper regions of a warm lagoon, or in the spring, warm air increases the temperature in the upper areas of a cold lagoon, it can cause mixing between the upper and lower zones, stirring up lagoon settled solids and releasing gasses that can result in unpleasant odors.
Symptoms of turnover can include the previously mentioned odors, floating sludge, and a darker color in the water of the lagoon. Usually, this is a normal and temporary process. Aside from resident objections to undesirable odors or possible elevated concentrations in the effluent, it is nothing to be concerned about. If the process lasts longer than a few weeks, additional underlying issues may exist.
If a lagoon is experiencing the symptoms of turnover for longer than a few weeks or during stable temperatures in the summer or winter, it is likely overloaded. For aerated lagoons, the first step is often to increase aeration times to introduce more oxygen into the treatment process. Another option is to switch to temporarily operating in parallel for lagoons that are performed in sequence. This can help to decrease loading on individual cells and give the overloaded cell time to recover. If the system has adequate storage capacity, operators may also want to consider recirculating effluent into the affected cell. This can help to dilute the lagoon and increase dissolved oxygen levels. In extreme cases, the affected cell may need to be bypassed or temporary aerators installed to remedy the problem.
Regular wastewater influent testing is essential. Consistent flow measurements can help operators anticipate and diagnose whether these symptoms are typical or the result of overloading. This can help operators remedy the problems before they get out of hand.
For regular seasonal turnover, lagoon facilities with repeated odor complaints from residents might consider establishing a community outreach plan. The plan should include explanations about how these types of systems work, why turnover happens, and the importance of wastewater treatment to a community, which may alleviate resident concerns and temper frustrations. Possible avenues for community engagement include local newspapers, social media or flyers. Although the plan may not prevent all residential complaints, transparency and readily available information may help residents understand what to expect regarding this vital part of their local infrastructure.
It is essential to have plans to deal with the many challenges a wastewater treatment system can throw at you. Being on the lookout for changes, knowing what is normal and what may require operational adjustments, and having a robust community engagement plan will go a long way toward dealing with challenges like lagoon turnover.
This is an age-old question that owners of septic systems seem to ask one another. Although misguided, there seems to be some sense of pride of ownership that the longer one can go without pumping their septic tank, the better, more robust system they must have. Not so. Please tell all of your friends!
A septic tank system needs regular maintenance, just like your car needs oil changes and spark plugs replaced, just like your HVAC system needs filters replaced and periodic checks by professionals. Think of your septic system as you would any other household system that needs some care and upkeep. Household wastewater contains disease-causing bacteria and viruses, as well as high levels of nitrogen and phosphorus. If a septic system is well-maintained and working properly, it will remove most of these pollutants. If not, a malfunctioning septic system can be a public health and environmental hazard by allowing exposure of harmful contaminants to humans, pets and the natural world. Not to mention, it is a violation of the law.Figure from EPA
Conventional septic systems are designed to be relatively low maintenance, but low maintenance does not equate to NO maintenance. A septic tank system is essentially comprised of five basic components:
A household collection system that removes all sewage from the dwelling and transports it out into the holding tank, or septic tank.
The septic tank is where the treatment of the waste begins, and its routine maintenance is an important step in the functional lifespan of your system. From the septic tank, the liquid portion of the sewage, called effluent, exits the septic tank, and moves out to the third component.
A distribution box, as the name implies, this box equally distributes the effluent as it moves out into the fourth component,
A drain field or absorption trenches.
Lastly is the soil, in which your septic system is installed, is the final step of treatment for a conventional septic system.
The septic tank works to “sort” the household waste as it allows for the contents to settle and separate. The solids settle down to the bottom of the tank, while the fats, oils, and greases float to the top. This action ideally results in no solids moving out into the drain field where they can potentially clog up the absorption trenches. If too much water is introduced into the septic tank at one time (i.e.., multiple consecutive loads of laundry), this can disrupt the settling time and potentially result in solids moving out into your drain field. Adequate settling time is important, so it is vital to keep this in mind in your routine household activities. Over time, the solids at the bottom of the tank accumulate and need to be removed. If the tank is not pumped out every three to five years, the holding capacity, and the ability to separate the waste will be diminished, thus creating a situation in which solids can more easily move into the drain field.
Septic tanks contain naturally occurring anaerobic bacteria which help break down solids in the tank and support the biological processes that treat human waste. Some people believe that they can reduce the frequency of septic tank pump outs by introducing “additives” to their septic system. There are different types of additives on the market. Biological additives add more bacteria to the tank, and in doing so, can create conditions in which the bacterial populations compete against each other, potentially causing negative effects. Enzymes are another type of septic tank additive. The enzymes are thought to aid in the breakdown of certain types of solids and limit the buildup of the scum layer (fats, oils, greases). Additives claiming to eliminate the need for pumping usually re-suspend solids, moving them to the drain field, thus clogging lines and leading to system failure. Septic tank additives are not regulated and there is no scientific evidence to support their benefit. A healthy septic tank should not need any additives, but again, it does need routine inspection and pumping every three to five years.
Some general rules of the road when it comes to caring for your septic system:
Use less water. Space out laundry sessions throughout the week. This avoids overloading the system over a short period of time. Be sure to notice any leaking toilets or dripping faucets and repair them right away.
Keep toxic chemicals from going down the drain. Properly dispose of solvents, paint, varnish, oil, and pesticides, instead of putting them down the drain. Use bleach and household cleaners sparingly.
Keep solids out. Cigarettes, left over medications, handwipes, feminine hygiene products, paper towels, tissues, kitty litter, and other solid items should go into the trash, not your septic system. Left over medications could kill the “good” bacteria in your tank.
Keep grease and fat out of your kitchen drain. Pour the oil into a container and dispose of it in the trash.
Limit use of garbage disposal. Using a garbage disposal increases the amount of water and solids in your septic tank, requiring more frequent pumping.
Divert runoff and drainage water. Never drain swimming pools or hot tubs into your septic system or drain field. Downspouts and roof runoff should be directed away from your drain field to limit hydraulically overloading the soil.
Regular maintenance pump fees can average between $250 to $500. This expense every three to five years is a bargain compared to the cost of repairing or replacing a failing septic system. Replacement costs can range from $5,000 to $20,000 or more depending on the type of system needed. A well designed, healthy septic system that is properly cared for should last a homeowner 20-30 years or more. Your septic system is a silent partner in keeping your home life humming. As lovable as your car, which you maintain regularly and as just as aggravating when it breaks down?! To find more information about being Septic Smart, go to: https://www.epa.gov/septic/septicsmart-week-quick-tip-videos.
In the world of wastewater collections, there are few things more cringe-inducing than the phrase “flushable wipes.”
Marketed as a convenient and efficient solution to sensitive tushes and germ-ridden surfaces alike, these fibrous and hard-wearing nonwoven wipes are the bane of rural and urban wastewater treatment facilities. In the thick of the COVID-19 pandemic, consumers have increasingly relied on these faux-flushables to keep their homes, schools, and workplaces clean. This has added to the headaches of system operators around the globe.
Once customers send these deceptively labeled disposables down the tubes, they cause havoc for public utilities’ vital equipment by enmeshing in plant screens and filters, weaving around impellers or combining with fat, oil, and grease (F.O.G.) to cause pump station clogs and other potentially catastrophic damage. As a result, budgets and labor hours are squandered, reducing systems’ operational efficiency and overall capacity.
In response, utilities have developed countless amusing and creative public information campaigns encouraging customers to think twice before flushing wipes. However, public media campaigns have their inherent limitations, and operators are ultimately responsible for taking the necessary precautions to prevent small obstructions from becoming crusty quagmires or all-out catastrophic events.
With these risks in mind, let’s revisit the fundamentals of routine pump maintenance. By extending the life of your pumps and improving their efficiency, you can prevent a nightmare scenario from occurring and potentially incapacitating your entire operation.
Wastewater lift station drop of knowledge pump flow test procedure
Calculate pump flow rates using volume and time calculations for wastewater lift stations without flow meters. First, inflow is measured with pumps off over a given time. Then one pump is started and how long it takes to pump the level down one foot is timed. Both the calculated inflow and pump down rate are combined for a total flow rate. Complete the test with the level close to the pump stop setpoint for worst case numbers. Periodic tests need to be completed at the same levels for comparable results.
Pump wet well down close to stop setpoint
With all pumps off, time how long it takes for the level to rise one foot
Start one pump and time how long it takes to pump down one foot
Repeat the procedure for all pumps
Calculate the wet well volume using the following methods:
0.785 x diameter2x depth x 7.48 (gallons per cubic foot)
Square or rectangle:
Length x width x depth x 7.48 (gallons per cubic foot)
Use these volumes per foot with inflow/pumping times to calculate pumping rate
0.785 x 6 x 6 x 1 x 7.48 = 211.4 gallons per foot
Inflow level rise 1 foot took 6 minutes
211.4 gallons ÷ 6 minutes = 35.2 GPM inflow rate
Pump down 1 foot took 1:15 minutes
211.4 gallons ÷ 1.25 (15 seconds is 25% of a minute) minutes = 169.1 GPM + 35.2 GPM inflow = 204.3 GPM total flow rate
Perform this test at regular intervals to monitor pumping performance more effectively.
The City of Faith is a small town located in Meade County, in central South Dakota, and is a hub for cattle ranching, general livestock, farming, and providing accommodations for visiting travelers. With a population of 421, the city has approximately 192 sewer/water service connections to residents and businesses. The famous dinosaur T-Rex called “Sue” was found in an area not far from Faith.
The City of Faith needed to refurbish its entire wastewater collection system to address significant inflow and infiltration problems within the system. The city also needed a remedy for the persistent clogging of pipes from tree roots, the corroding condition of system manholes, and the improper connection of sewer service lines. The original wastewater collection system was installed in the 1920s using vitrified clay piping. In recent years, a few short segments have been replaced with newer pipe; however, the vast majority of the system (over 80%) is original material and is showing signs of significant deterioration. A Preliminary Engineering Report recommended the best option to remediate the city’s sewer collection issues was to “slip-line” the existing sewer collection piping and replace the corroding system manholes. Sliplining is a technique for repairing leaks or restoring structural stability to an existing pipeline. It involves installing a smaller, “carrier pipe” into a larger “host pipe”, grouting the annular space between the two pipes, and sealing the ends.
The city did an excellent job of long-term planning for the project. Over the last several years they were able to save $500,000 to contribute to the almost $2,000,000 project. MAP worked closely with the city and the local planning district, Black Hills Council of Local Governments, to access additional public financing for the project. With this assistance, the city was able to obtain a Community Development Block Grant (CDBG) for $515,000, a USDA Rural Development (RD) grant for $116,836, and a low-interest loan from USDA RD for $829,000. Coupled with the city’s $500,000 contribution to the project, the completed financing package made the project feasible and affordable for the community.
MAP provided technical assistance to the city in the bidding phase and during project construction, with the goal of ensuring the project moved along smoothly. Due to the multiple funding sources, it took coordination among organizations to ensure the funds were spent in the correct order.
When MAP asked Debbie Brown, Finance Officer for the City of Faith, about the project’s financial impact to the residents and businesses, she stated, “due to long-term planning and being able to leverage funds, the overall impact to the local residents and businesses was minimal and rates remain affordable for the city’s customers.”
The community’s long-term outcome of this project is they can provide dependable wastewater services to the residents and businesses in the City of Faith. The repairs to Faith’s wastewater system ensure the ongoing safety and health of the individuals living in the community.
On October 3, Knox County (Ohio) Water and Sewer generously hosted a site visit to the Bladensburg Sand Bioreactor Wastewater Treatment Plant. We had great weather and a great discussion both on-site and afterwards at the Bladensburg Community Center, where Dr. Karen Mancl from Ohio State University presented slides that highlighted the differences between the single-pass and multi-pass designs of sand bioreactors. Some highlights from both discussions are below:
All the nearly 90 connections are served by septic tanks (individual, shared, and some cluster) and a small diameter sewer collection system. Half of the community’s flow is collected at a pump station due to elevation, then pumped up to the recirculation tank at the site of the sand bioreactor. The other half of the community’s flow is via gravity straight to the recirculation tank at the front of the sand bioreactor.
Recirculation allows the reactor to fit on a smaller footprint. It effectively increases the depth of the reactor by passing the influent through the same depth of media several times. On average, the raw influent makes up about 1/5 of the flow in the reactor, where the rest of the flow is already in some part of recirculation.
High flow – Rain Events
When there are heavy rains as is not uncommon in this ‘rain belt’ part of Knox County, the flow (raw influent and recirculation) that passes through the media is discharged more frequently, which means that some of that flow is not completing the average 5 trips through the media that is seen during normal/dry flow conditions. This is accomplished by a sort of float valve that diverts flow to the outfall when the discharge chamber fills to a certain volume. During normal flow conditions, flow continues to recirculate until that float valve raises to the necessary height in the tank to then divert flow to discharge. Jeff and Greg from the Bladensburg plant have not seen effluent quality suffer during these heavy rain events. However, if heavy rains were to continue for a long period, such as a month, as discussed later in regards to the control panel, then treatment performance will suffer. Also, they both noted that they do not see notable I&I in their collection system (i.e. the pump run time at the pump station and recirculation tank do not vary much from dry weather flows during heavy rains). Additional flow during rain events is believed to essentially only be rainfall caught by the sand bioreactor field itself. Professor Mancl noted that sand bioreactors are great options in areas with highwater tables or problematic soils since the bioreactor is lined with a membrane and is not affected by groundwater.
A big question from some operators and engineers leading up to this site visit had been what the headworks for a municipal sand bioreactor consists of. When discussed at Bladensburg, staff explained that there is no screen for grit removal like mechanical plants. Essentially, the septic tanks prior to the small diameter collection and the baffles at the pump station and recirculating tank serve to capture grit and protect their pumps. This design has been effective for their system’s 10 years of operation. However, they did emphasize that in hindsight they would have preferred to have all flow go to the pump station and to have a shallower recirculation tank. Staff explained that the tank is around 20 feet deep due to elevation needs to receive the gravity flow, which creates difficulties in servicing the tank and safety concerns. Even though sending the flow from the other half of town would mean roughly doubling the energy used for pumping, staff believe it would be well worth it to facilitate O&M.
Related to this point, Professor Mancl explained that smaller sand bioreactors could have been located at the site of the pump station and elsewhere, so that sewage doesn’t need to be pumped, just the treated effluent, which is just as easy to pump as drinking water and to have the treated effluent flow to single outfall (as was done with a fixed media treatment system in Amesville, Ohio, though they used textile media rather than sand).
The outfall is down the short hill from the bioreactor and is fed from a pipe that transmits flow diverted by the float type valve next to the recirculation tank. The outfall pipe also has a flap that flow pushes open, but is heavy enough to prevent muskrats from entering the pipe. We all noted the low flow of the creek and commented on how high quality the effluent must be to not impact the stream (Wakatomika Creek) water quality. Jeff agreed and provided a copy of the publicly available MORs.
The main difficulty that Bladensburg has had with its system is the Siemens control panel. It has not been reliable for them and at one point they had to manually control dosing for about a month. During that month of operation, they would rotate where dosing was occurring on the sand bioreactor approximately two times per day, rather than the control panel having each pump rotate through its 4 different spray application lines. This meant that the sand bioreactor did not receive the intervals of oxygen reaching the microorganisms between doses and effluent quality was observed to be poorer during this month. During normal operations, the pumps and manifolds do the odd numbered application lines one time (2 minutes of application followed by 9 minutes of rest), and then it doses the even lines on the next cycle, repeating this cycle over 24 hours. This allows time for air to diffuse throughout the bioreactor.
Best practices and Cost Considerations
One of the cons of a sand bioreactor is that they do require periodic weeding, which as all gardeners know, is a tedious task. While the operator has difficulty meeting time requirements at the plant because there is not much to do, outside of sample collections, the O&M of weeding was an obstacle to the County choosing to install another one of these systems. Professor Mancl shared suggestions based on her research and the success of the Harrison, Ohio, in using a large plastic covering to kill the weeds and weed seeds that you move from section to section of the bioreactor every few weeks. The more recent solution that Harrison uses is to allow goats to weed the bioreactor.
Another best practice that Professor Mancl shared was during the flushing of the application lines that apply the waste to the sand to install quarter turn valves on the ends of the application lines and to cut a pvc tool and hook you can use from a standing position to open the caps and turn the valves. This avoids having to get on your hands and knees to open the caps and turn the valves by hand.
Professor Mancl also noted that the < 2.0 uniformity coefficient of the sand that was used in the installation added a lot of unnecessary cost to the project. The price jump from 3.0 or 4.0 (recommended and cheaper) to 2.0 is big.
Both Bladensburg and Harrison have noted that U/V bulb fouling has been very slow, only requiring wiping down of bulbs 1-2x / year.
Jeff also said he was very skeptical of this system since he had not worked with one before becoming the engineer for Knox County Water and Sewer. The sand bioreactor had already been up and running for about 4 years when he joined, but he said it has proven itself reliable and effective and that he “would definitely recommend it”, despite having had one lingering question. He wasn’t sure if he needs to plan to replace the media and wasn’t sure if the increase in total dissolved solids was cause for concern, which normalized at a higher level than when the plant originally began operations. Professor Mancl explained that the TDS is indicative of salts and hypothesized that more water softeners may have been installed in the community and could explain the new higher TDS, especially in the context of such a small customer based (around 90 connections). Regardless, she pointed out that TDS has not caused any difficulty in meeting permit/plant performance requirements. Professor Mancl may not have commented specifically on the media replacement question, but from previous conversations with her it is understood that the media shouldn’t need to be replaced as long as it is the proper non-limestone sand and is dosed properly.
The sand bioreactor is roughly 40 x 400 ft or around 1/3 of an acre. The spacing of rows of solar panels was explained as well as how around $10,000/ year pf potential energy offset could be generated by installing a little over 300 panels on that space, assuming $0.10 kWh. The county administrator was also present, and we discussed the County’s interest in solar and its potential on this site. Jeff had expressed an interest in it if the payback period can be achieved in 10 years or less. This may be something worth looking into further.
It’s our hope that by sharing stories of lessons learned both good and bad, we can help small rural communities choose the best infrastructure solutions that meet their needs. On October 27, Ben Howard from GLCAP is delivering a webinar to the rest of the RCAP network that will share cover what has been learned and discussed by the Alternative Wastewater Solutions Committee regarding sand bioreactors. If you would like to join, please register here.
By Traci McQuary, Mississippi State Coordinator, Communities Unlimited (CU)
According to the U.S. Environmental Protection Agency (EPA), approximately 18 million households, or 25% of all households in the United States, dispose of their wastewater using onsite and decentralized wastewater systems, more commonly referred to as septic systems. The performance and maintenance of these systems are a significant concern for homeowners and the environment.
Although state and federal laws set minimum environmental and health standards, local officials and individual homeowners are responsible for protecting themselves and their communities from wastewater-related illnesses, like E. coli, Salmonella, and Cholera. Septic system owners are ultimately responsible for the operation, monitoring, and maintenance of their onsite septic system.
Septic systems that are not properly maintained will fail, leading to significant environmental and health concerns. Failing septic systems allow untreated sewage to pool on or under the ground. This poses a health risk to children, the elderly, the environment and provides an ideal breeding ground for flies, mosquitoes, and other disease-carrying insects. It can contaminate nearby water sources and wells. Outbreaks of waterborne illnesses are frequently traced back to contaminated groundwater.
In many states, local health departments issue permits to install septic systems according to state laws that govern public health protection. Under most regulatory programs, the local permitting agency conducts an initial individual site assessment to determine whether sufficient space is available and checking that the soil type can provide adequate treatment. These programs also establish guidelines to ensure that groundwater resources will not be threatened, and specify the appropriate distances from groundwater wells, buildings, driveways, property lines, and surface waters such as ponds or lakes. however, very few permitting agencies conduct inspections after the new septic system is installed, nor do they implement management programs to monitor the continued upkeep and functionality of septic systems while the system is in use.
Unfortunately, the current regulatory structure throughout much of the nation lacks the enforcement of acceptable performance of septic systems, so homeowners need to conduct regular maintenance on their septic systems. The most cost effective and long-term option for meeting public health and water quality goals in rural America is for homeowners to have a regularly scheduled inspection to certify that their septic system is being adequately maintained. Repairs are often left undone because homeowners cannot afford them, or repairs are done by the homeowner who is often not an expert in onsite systems.
To ensure that homeowners have correct and up to date information to maintain, operate and keep their septic system performing to satisfactory standards, the following are some examples that individual states, tribes and local governments could do:
Improve homeowners’ understanding of the role decentralized systems play in protecting local water quality and public health;
Support homeowners in suburban or rural communities in meeting their infrastructure and development needs by providing outreach and education materials on decentralized technology. The EPA offers materials and resources on their website called SepticSmart. They provide homeowner education on septic systems and promote awareness in caring for them. https://www.epa.gov/septic/septicsmart-homeowners;
Improve local decision-making through improved public awareness, education programs, and information material. RCAP can provide classes specific to each state or territory for homeowners like Decentralized Wastewater (Septic Systems) Basics for Homeowners.
If you or your community have questions or concerns on your onsite/decentralized systems, please contact your local RCAP office as we have resources for both TA and training to help protect public and environmental health for you, your family and your community. Many areas across the country have server challenges with septic systems and wastewater disposal. RCAP will be helping provide training and technical assistance as part of EPA and USDA “Closing America’s Wastewater Access Gap” Community Initiative.
Is your community effectively operating profitable and sustainable water and sewer systems, or are you simply getting by? With our communities’ ever-changing dynamics, our rural drinking water and wastewater systems will need to implement new administrative strategies and management tools to adapt to the increased regulatory requirements and environmental complexities they face daily and into the future. As responsible community leaders, we must allow the systems to operate using a “business model” for long-term sustainability. Sustainability will help address new and stricter regulatory requirements, changing populations, increased service demands, limited water supplies, a highly variable climate, aging infrastructure, and limited state and federal funding.
Cost estimates for water and wastewater system needs in the rural U.S. total billions of dollars nationwide. The existing state and federal funding sources can only meet a fraction of this need, even with the new influx of infrastructure dollars through the Bipartisan Infrastructure Law (BIL). Therefore, approaches to reducing the gap between what is needed and what funds are available will need to be adopted. In addition, funders want assurance their investments in water and wastewater infrastructure will be adequately managed and maintained to ensure long-term sustainability and security. This assurance will require water and wastewater systems to present convincing evidence that they possess adequate financial, technical, and managerial capacity to maintain/sustain the infrastructure necessary to provide the service their customers expect. State and Federal funds only cover the cost of capital outlays, but not ongoing operation and maintenance over time. In addition, the new or upgraded system must remain in full compliance with the Safe Drinking Water Act (SDWA) or the Clean Water Act (CWA), and any additional state or local regulations.
It is recommended that systems adopt a “business model” for managing the delivery of services. This plan should include:
A five-year financial plan with a fully allocated rate structure;
An asset management plan;
A water accounting system with full metering;
Full compliance with the Safe Drinking Water Act (SDWA) or the Clean Water Act (CWA), and your state primacy/regulatory agency requirements ;
A governance structure adequate for proper management and oversight; and
Participation in regional efforts to collaborate on long-term solutions.
A financial plan has two components: a forecast of the utility’s future financial needs (such as operating and capital needs) and an identification of how to fund those future financial needs.
A Capital Improvements Plan (CIP) is a written document that specifies and satisfies the following questions and is typically based on a utility’s asset management program:
What facility improvements will be needed in the future?
When will the improvements be needed, and when will they be undertaken?
How much will the improvements cost?
What financing options are available for the improvements?
A CIP is a multi-year planning document that identifies capital improvement needs and is usually done in 5-, 10- and even 20-year increments. This will help your utility’s board and management make informed decisions about rate setting, future debt-service requirements, and future revenue requirements. In preparing a CIP, there are several things to consider:
Will current facilities reach their design capacity soon?
What new equipment, services, or facilities are needed to meet the demand of your customers?
What current system components will require significant repair, rehabilitation, or replacement?
Will failure to upgrade existing facilities result in regulatory violations or enforcement actions?
What are the most critical improvement needs, and what is the urgency of meeting those needs?
What benefits do the improvements provide to the system and its customers?
What are the available options for financing the improvements?
Can regular resources of the systems fully fund future capital projects, and which projects will require outside financing?
How do financing options for improvements relate to the annual budgeting process?
Use the assistance of a consulting engineer to prepare cost estimates for major capital improvement projects that the community will need in the future.
RCAP and Midwest Assistance Program, Inc. (MAP), RCAP’s regional partner, assists communities by being a resource to help plan, prepare, and execute a comprehensive strategy to sustain your community’s system(s) now and into the future. To be a good steward of your infrastructure, technical, managerial, and financial responsibilities are interconnected – one cannot be sustainable without the other. As a community leader, you need to enable the community to “look around corners” to identify potential expenses and maintenance to their systems and provide a fair and equitable rate structure for the community to “invest” in the future of your most valuable resource.
RCAP’s Managerial and Financial Hub has resources on management, rate setting, applying for infrastructure funds, and regionalization.
A Guidebook of Financial Tools. USEPA, Environmental Finance Program.
The Basics of Financial Management for Small-communities Utilities. RCAP Rural Communities Assistance Partnership.
Small System Guide to Developing and Setting Water Rates, Rural Community Assistance Program, Inc.
Rate Setting and Capacity Development, the Environmental Finance Center at the University of Maryland.
There are over 8,000 wastewater lagoons permitted to treat raw sewage in the United States. Most wastewater operators will tell you that the low operation and maintenance (O&M) cost of a lagoon is a significant advantage over a package plant or other mechanical treatment process. But it’s important to note that low O&M costs should not equate to no O&M. The key to keeping O&M costs to a minimum is to be proactive with your maintenance instead of reactive.
Lagoons tend to be more neglected than other types of wastewater treatment facilities. “Out of sight, out of mind” seems to be the common philosophy among many wastewater operators. The problem with this is that without regular inspection and proper maintenance, the lagoon will fail, and the community’s wastewater will not be adequately treated. This can lead to compliance issues when the effluent doesn’t meet the permit limits, and even public health issues if untreated wastewater flows into public streams.
One’s O&M needs will vary depending on many different aspects such as the type of lagoon, the size of the facility, how many cells the lagoon has, the type and amount of waste you are treating, and the equipment used in the treatment process. Even though it’s not required in many states, we highly recommend that an operator does a daily inspection of the facility.
Performing Daily Inspections
In the daily visit to the wastewater treatment facility, the operator should inspect the lagoon for scum, grease clumps, and other floating items that can block the pipes.
The operator should also be aware of any new or unusual odors that could indicate a problem in the treatment process, such as a malfunction of an aerator or chlorinator. Odors can also indicate an algae overload, an influx of septic water from the collection system, illegal dumping, a dead animal, or many other things that might require additional investigation/action. Plus, if your pond is near any residences, odor control must be a priority.
Other things to do during the daily inspection include:
Inspect and clean the bar screen at the headworks
This will prevent unwanted solids from entering the lagoon from the collection system
Check for blockages by confirming flow into the facility and between cells of the lagoon
Pipes can collapse and cause a blockage
Pipes can be blocked by animals including turtles or a build-up of solids
Inspect aerators and curtains/baffles to confirm they are anchored in place as designed
Weather can damage these devices by moving them around and interrupting power service, which interferes with their effectiveness in the treatment process
Check the chlorine pump/feeder, including any chemicals fed in the treatment process
Check site for gas chlorine leaks
Ensure the supply of chlorine and other chemicals is sufficient
Make sure the chlorine contact chamber is clean and free of any sludge or debris
Too much sludge can lead to sludge bulking in the chamber, causing high total suspended solids (TSS) levels and other parameter deviations
Maintaining the Landscape
Maintain the grass on the levee/dike/berm on a regular basis, depending on your location and the time of year. Cutting the grass around your lagoon regularly is extremely important to prevent the clumping that occurs when you allow grass to grow very tall before you cut it. Clumping can lead to erosion because of uneven grass coverage. The grass on that levee should look like a well-groomed lawn!
Repair any holes in the levee as quickly as possible.
Do not allow trees to grow on the levee/dike/berm. Their roots can penetrate the levee, causing costly damage. When possible, remove any tree within 50 feet of your lagoon. Trees can block natural airflow, which can affect the dissolved oxygen (DO) transfer in the lagoon, which in turn can affect the health of the bacteria in the lagoon.
Aerators and curtains/baffles should be serviced regularly as required by the manufacturer.
Last but not least, check the fence around your facility. There should be no holes in the fencing and no evidence of burrowing under the fence. Always lock the gate when you leave the site.
Taking these steps will ensure that the O&M costs of your lagoon remain low, and the facility continues to operate in top shape.
Low-pressure systems operate like normal sewer systems. They take in the normal waste from a home and/or commercial building, but before transferring it straight to the treatment plant, it makes a stop through a grinder pump. A grinder pump is kind of like your garbage disposal. This high-powered pump can run by an “on/off” sensor level switch or a float system. Once the pump kicks on, it grinds up solids before pumping waste out through the discharge line. Toilets, baths, showers, household sinks, dishwashers, and washing machines are all examples of WASTE that the grinder pump needs to handle—it has a big and important job to do.
A grinder pump station/unit consists of a basin that houses the pump, where an inlet from the home/building enters. This pressure system consists of a pumping station “grinder pump unit” on each property (could be shared), which is connected to a discharge line that is connected to a network of force mains. Those lines then transfer the wastewater to lift stations and/or treatment plant.
Like a Garbage Disposal Except…
Now, most manufacturers will tell you that their grinder pump is made to grind up a beer can. However, in my experience working with grinder pumps as an operator in the field, I learned that was just a sales pitch–these pumps are powerful, but not that powerful.
A grinder pump station/unit is kind of like your garbage disposal, but stronger. Grinder pumps are 1-2 Horsepower (HP) or more and garbage disposal are about ½ HP. They are also designed very similarly – a grinder pump is facing downwards and the garbage disposal is upwards. Consider the times you turned on your garbage disposal to find something was down in there that wasn’t supposed to be! We’ve all seen what our garbage disposal has chewed up, whether we wanted it to or not! The main difference between them is that our garbage disposals are eating up and discharging the waste as we control the running water, whereas the waste from our homes are filling (settling/floating) into a basin where the grinder pump sits quietly until the level of the waste triggers the pump to kick on. We try to manage what we put into the garbage disposal, because we know what can happen, and we operate it manually. But many homeowners may not even be aware they have a grinder pump and how it needs to be cared for until it needs to be fixed. With a grinder pump, what we flush is out of sight, out of mind and when the grinder pump clicks on is beyond our control!
The Problem with Floating
When items have time to settle, they have a better chance of being chewed up and pumped out by the grinder pump without issue. Since the grinder pumps operate on levels, anything that stays afloat will continue to collect. That means that if you then add grease, powder detergents, etc. to what is already floating, you are forming a solid which may create challenges in the grinding process. Most problems that occur with grinder pumps are due to unwanted items being placed, thrown, flushed, etc. into the sewer system.
To avoid and prevent problems to the grinder pump including blockage and damage to the system itself, it’s important to help educate our communities on what can’t be flushed down the drain.
A DO NOT Flush List
Below is a basic list of common items you SHOULD NOT put and/or place down/into the sewer. Please note that this list can also apply to those served by a public sewer with or without a grinder pump, as well as to individual septic systems:
Diapers (children or adult)
Disposable Wipes (even if they say “FLUSHABLE”)
Paper Towels or Rags
Feminine Hygiene Products (even if they say” FLUSHABLE”)
Abrasive Materials including Gravel, Sand, Aquarium Rocks
Gasoline or Diesel
Sump Pump Connection
Storm Water Runoff
A Few Helpful Additional Notes for Technical Assistance Providers (TAPs), Operators and Property Owners on Grinder Pump Stations:
Allow access to grinder pump station/unit at all times.
Do NOT cover vent to pump station/unit.
Do NOT cover pump station/unit lid.
Do NOT turn off the power to the pump station/unit.
Always call Digsafe at 811 before digging!
If you lose power, notify your utility ASAP!
If you do go on vacation or this is a vacation home: Flush the system before you leave to prevent clogs in the pump when you return!
Run water into the grinder unit until the pump kicks on.
Turn off the water going into the grinder unit, allowing the pump to run until it shuts off automatically.
If you disconnect power, please notify all your utilities.
Teaching, educating, and simply knowing your system can make a huge difference for everyone.