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We are going to go out on a limb here and guess that you are among a legion of households that own a dishwasher. This is hardly surprising because dishwashers certainly have their advantages. Instead of laboring over the sink scrubbing and rinsing, you can simply load your dirty dishes and glasses into the machine, and with a press of a button, the dishwasher does all the work. Interestingly, the U.S. Department of Energy estimates that a dishwasher can save one up to 230 hours each year — time that can be devoted to leisure or a whole host of other things. The decision of whether or not to purchase a dishwasher could be easy. However, if you are one of likewise millions that are not connected to a centralized public sewer system and rely on on-site dedicated septic systems, it would help to know the effects of a dishwasher on a septic system.
What dishwasher machines are best for septic systems? The best dishwashers for households that rely on septic systems are those that are certified energy-efficient because these consume substantially less water. If you don’t know this yet, the less water you allow into your septic system, the better. Excessive water in a septic is a leading cause of system failure. The soil beneath the septic system must absorb all of the water used in the home and too much water from the laundry, dishwasher, toilets, baths, and other fixtures may not allow enough time for sludge and scum to separate inside the septic tank. Flooding a septic tank and field with excessive volumes of water may disrupt the normal decomposition process; the flooding may move the essential bacteria away from their food source. The less water utilized in the property, the less water enters the septic system, lessening the risks of system failure.
In a fully functional, well-maintained septic system, the volume of water from dishwashers are typically not an issue. However, there are particular conditions under which you should avoid draining dishwasher discharge into a septic system:
- Limited drainfield capacity. If your drainfield (or leach field) has limited capacity to absorb effluent, it is best to divert your dishwasher discharge away from it. Smaller drainfields may not be built to process beyond the typical household water usage (bath and kitchen) of a small family.
- Symptoms of drainfield failure. If there are indications of drainfield failure (effluent seeping to and pooling in the surface of your yard or effluent backing up into the home or building), dishwasher discharge needs to be diverted elsewhere. At even the early warning signs of drainfield failure, you should get your system inspected and repaired immediately.
If you have one or both conditions listed above, one option you have is to have a separate greywater system or drywell installed, designed to receive dishwasher discharge. If you are considering this step, you may as well want to divert your clothes washer to this common drywell, too. The more limited your septic drainfield capacity is, the larger the drywell should be.
Dishwashers and Septic Systems: How to Make Them Work Together
You can certainly run a dishwasher on a home septic system – provided that your system is properly functioning and regularly maintained. The additional water from the dishwasher will normally not overload a fully-working system. Furthermore, the detergent content of the dishwasher wastewater is ideally diluted, or else it may harm the bacteria within your septic system. It is for this reason that you should use only septic-safe dishwasher detergent.
If your home or business property runs on a septic system and you are contemplating adding a dishwasher, first make sure that your drainfield is working properly and is not showing any signs of failure. Signs that your drainfield may be failing include pooling of effluent within the property, sewage back-ups into the home, and foul odors. If you are unsure if your drainfield has sufficient capacity to absorb effluent, it is best to ask a septic service provider to inspect and assess the situation. They should be able to make informed recommendations, too.
If you confirm that your drainfield is not able to handle additional effluent from a dishwasher, consult with your septic provider about having a drywell (also referred to as greywater system) installed. The wastewater from your dishwasher will be discharged into this drywell instead of the septic tank. Again, if you do decide on having a drywell installed, it’s a good idea to have your clothes washer empty into it, as well.
If you now have a dishwasher machine, do opt for liquid, eco-friendly dishwashing detergents. These will help in keeping the essential bacteria in the septic system healthy and thriving. Also, these are better for the environment (which will, eventually, receive all the substances that go with our wastes). Relatedly, only run your dishwasher with full loads so as to maximize each operation.
Look for an energy-efficient dishwasher. These use significantly less water which helps avoid overloading your system with effluent. Some of these dishwasher machines even feature a booster heater that conserves even more energy, translating to more savings on utility bills. Booster heaters heat the water to the recommended 140ºF before it even enters the dishwasher. A dishwasher with a booster heater may be a bit more expensive out of the box, but it does pay off as you save on energy and utilization. It is always safe to go with a dishwasher machine that has the Energy Star seal. Energy Star is an EPA and DOE program that promotes energy efficiency in properties and equipment. The minimum federal energy standard (Energy Factor or EF) for dishwashers established by the Department of Energy is at least 0.46 cycles/kWh for standard-size dishwashers for the “normal” cycle. Therefore, a standard-compliant dishwasher would use 2.17 kWh per load of dishes. Energy Star certified dishwashers have an EF of 0.65 or higher so that they would use 30% less energy than a standard model.
Below is a list of energy-efficient (thus, water-saving) dishwasher machines that several septic experts and professionals recommend.
The SPT Countertop Dishwasher has a spacious cavity that holds up to 6 standard place settings capacity with built-in dish rack and silverware basket. It has 6 wash cycle settings: heavy, normal, light, glass, speed, and soak. It is built with a durable stainless steel interior and spray arm. You get easy controls and water temperature up to 148ºF. It quickly connects to any kitchen faucet, eliminating the need for direct plumbing or permanent installation procedures. Faucet adapters included for convenient connection.
PRO: This compact, yet powerful, countertop dishwasher from SPT is perfect for apartments, office kitchens or any small-sized kitchens. With a height of only 17.24”, this unit will fit between most countertops and cabinets.
CON: The compact chassis means you won’t be able to auto-wash the bigger mixing bowls or bulky prepware. Otherwise, if you run a load with just a big bowl in the machine, that’s just not optimized water and machine usage.
You can wash up to 6 standard place settings right on your countertop with the EdgeStar DWP62. This compact countertop dishwasher has a low profile that fits comfortably under most cabinetry without the hassle of permanent installation. It includes a dish rack, cup shelf, and cutlery basket. EdgeStar DWP62SV can hold plates that are up to 10.5″ in diameter. It has 7 wash cycle settings and a quick-connect adapter that will fit standard-sized kitchen faucets. The built-in rinse agent dispenser helps to minimize water spotting on dishes, while its internal water heater and the heavy wash cycle helps to eliminate germs and bacteria Water consumption (in normal wash setting) is only 2.85 gallons.
PRO: This EdgeStar portable dishwasher is made with a stainless steel interior, allowing for a seamless and stylish addition to any space. Users particularly like its powerful spray arm that thoroughly washes dishes and glassware.
CON: Some users have observed that this unit’s plastic parts (like the water hose and utensil basket) are more susceptible to wear and tear and prone to breakage.
The Black+Decker BCD6W Compact Countertop Dishwasher has a 6 place setting capacity and can accommodate plates of up to 10″ in diameter. It features a crisp LED display with Electronic Touch Controls for easy and precise adjustments. With this, you have 7 wash programs: Intensive, Normal, Eco, Glass, 90 Minutes, Rapid, and Soak. It is built with a slide-out dish rack and removable utensil basket that allow for easy loading and unloading. Child Lock + High-Efficiency Rating and Energy Star Certified.
PRO: This compact dishwasher is space-saving and its stylish design makes it an attractive addition to any room. Perfect for maximized limited living spaces.
CON: Product may not be as durable to withstand rough handling during shipping. A number of dissatisfied customers have complained about receiving damaged items which does not reflect on the brand itself.
This Compact Countertop Dishwasher from hOmeLabs easily sits on even small countertops or tabletops. It features a quick-connect assembly and accessories including inlet and drain hose and a faucet adapter for water lines. It features a simple control panel and convenient light indicators. The program selector has 6 wash cycle options: heavy, normal, ECO, glass, speed, and rinse. hOmeLabs features a delay button light to postpone the wash cycle. Truly, a convenient and compact Energy Star-certified dishwashing machine for cleaner dishes.
PRO: This countertop appliance measures 17.2 x 19.6 x 21.6 inches with 6 place setting capacity makes it a perfect option for small-sized households or apartments with limited spaces.
CON: A few dissatisfied users have observed leaking in some units. The housing and seals made of plastic were more prone to wear and tear so may not last very long.
This convenient dishwasher from Farberware has a 6 place setting capacity, making it ideal for small-sized houses, apartments, dorms, boats even campers and RVs. The 6-place setting capacity allows you to wash a variety of dishes (up to 10” in diameter) and includes folding down rack shelves, plus a cutlery basket. Even as a countertop, compact machine, it offers full-sized dishwasher cleaning in 7 wash settings (heavy, normal, baby care, light, glass, etc.). This Farberware Professional features a quick-connect assembly with accessories and adapters included.
PRO: This product features an extra-drying function. It adds extra heat to the final rinse for improved drying results. Another notable advantage is its Child-lock option that allows you to lock the buttons on the control panel so children are safe from accidentally starting the machine.
CON: A few customers have complained about leaks within the unit. An observation is that its less-than-optimal placement of tank-filling hole makes avoiding drips and spills a frequent occurrence.
Equipped with Bosch PrecisionWash, this Integrated Pocket Handle Dishwasher has intelligent sensors that continually scan and check the progress of dishes throughout the cycle, working together with powerful, precision spray arms to target every item in every load. It is built with a removable silverware basket that’s perfect for loading utensils and cutlery. This unit also has Bosch’s Flexible 3rd Rack which features expandable wings that easily lower as well as adjustable tines allow you to customize the rack’s loading space, making it easy to load the more bulky or deep dishes or prepware.
PRO: Bosch dishwashers are known for their exceptionally quiet operation, so running the dishwasher is never a disruption. Bosch dishwashers are built with multiple insulation layers, grind-less food filtration, Bosch EcoSilence motor system, and a sound-absorbing base.
CON: A little high on price scale, compared to other dishwashers in its class. However, you can be sure, too, that you are paying for quality and the guarantee of a world-trusted brand.
This fully-integrated dishwasher that is Bosch Built-In Bar Handle Dishwasher has the all new revolutionary AutoAir option. Its Bar Handle design adds stream-lined aesthetics to your kitchen or pantry. It is a great cleaning machine with simple-to-use, intuitive button controls as well as an array of cutting edge features, one of which is the AquaStop leak protection that works round-the-clock to prevent water damage.
PRO: This unit features what Bosch units are known for: a flexible third rack with fold-down sides to allow for up to 30% more loading capacity. Its FlexSpace Tines fold back to accommodate the larger pots, pans deep dishes, and curved plates. The EasyGlide rack system provides a smooth glide for easier, more convenient loading and unloading. Quiet operation, too.
CON: May not be the best at drying the dishes after just one wash cycle. Although, this likely has to do with shape/size/quality of dinnerware, not to mention how long food residue has been left on.
Putting in a Drywell for your Dishwasher
A drywell (sometimes called a soakaway or a soakwell) is a covered pit with a perforated lining that accepts and holds water, typically from stormwater runoff. It has become a viable option where dishwater discharge and, possibly, other sources (like laundry and other greywater), and allows it to seep gradually into the ground. A drywell is a viable option for homes or properties with on-site septic systems with limited drainfield capacities.
If you meet one or both of the drainfield conditions as discussed earlier in this article, you might decide to install a drywell. If you have, here is what you need to know about drywell installation, starting with a quick list of the things you will need:
- Drywell liner
- 4-inch PVC pipe
- 4-by-2-inch wye fitting
- 2-inch ABS or PVC cap
- Plastic pipe cement
Pinpoint a location on your property with good drainage. The subgrade soils’ permeability rate must be sufficient in that it is able to drain the stored runoff within 72 hours. Once you’ve determined the location, dig a hole that is about 6 to 8 feet deep and a diameter of 4 to 10 feet. Drop in a fiberglass, plastic or concrete drywell liner.
Next, with a shovel, dig a trench from the top of the drywell liner to your house, and lay a 4” PVC sewer pipe from the liner to a point just outside the house. Inside the foundation is more preferable, though. Note to keep a minimum grade of 1/4 inch per foot on the sewer.
Backfill this sewer trench and drywell with dirt, completely covering them. It is important to make a note of the drywell’s location (as well as its components) on a property map in case you ever need to dig it up in the future.
Re-route the sink drain into which your dishwasher empties from the main sewer pipe and to the one that travels to the drywell. You can make the connection to the drywell sewer with a 4 x 2 inch wye fitting. Close up the previous connection by gluing on an appropriate 2” ABS or PVC cap with plastic pipe cement.
If you have optimal soil conditions and, thus, good drainage, do consider routing other greywater sources, such as bath and clothes washing machines, to the drywell. Doing so can extend the life of your drainfield for years as a drywell relieves it of significant load. Your trusted septic service provider should be able to help you determine if your property has sufficient soil conditions for a drywell.
Just remember not to dig a dry well in a location with a high water table, or else it may overflow. You can usually identify high water areas if you observe the exceptionally lush vegetation when everything else is parched.
Home Appliances that could be Hurting Your Septic System
With the influx of modern, high capacity appliances in households these days, there is an increase in risks to your septic system without us even knowing. By the time that you realize the combined impact of all these equipment, you may already be knee-deep in backed-up sewage and making a frantic call to your septic professional for emergency assistance.
Of course, we hope this never happens to anyone, so it pays to stay informed. There are two primary factors impacting the health of septic systems: increase in unwanted solid wastes and excessive water flow. While these factors can hurt the function and flow of a septic system as a whole, they definitely affect the way your septic tank’s ability to treat household waste.
We’ve listed down the top 5 home appliances/devices that have the most potential to overwhelm your septic system. They can provide much added strain on your septic tank and drainfield to a point of requiring frequent maintenance repairs, just to avoid system failure.
Clothes Washing Machine. This is probably the leader in septic system failure culprits. Even if you have an energy-efficient model that uses less water, the build-up of lint that makes its way to the septic tank can cause the system to fail. A factor in the rapid build-up of lint is the frequency in which laundry washing is done in the house. Mitigate this by spreading out your laundry loads over a few days instead of doing heavy laundry loads at one go. By doing several small loads rather than one huge load, you lessen the likelihood that a lint build-up will clog up the septic tank.
Dishwasher. Much like the washing machine, newer dishwashers are more efficient and utilize significantly less water, which is ideal for septic tanks. With that, it’s the dishwasher detergents that are often the cause of septic-related trouble. It is always best to look for eco-friendly, septic-safe dishwasher detergents. And similarly to the washing machine, be discerning with your use of the dishwasher. It is recommended that you use the dishwasher in evening, particularly as the household is asleep, when you are not using water with other appliances or fixtures. This will spread out water flow to the septic tank and give it the chance to work more efficiently.
Hot Tub. A hot tub holds a substantial volume of treated water, and although this may not pose an immediate threat to the septic system, it does when it’s time to drain it. This high volume of treated water can overwhelm the septic tank when drained rapidly. The amount of drain water from the hot tub could disturb the solid wastes in the septic tank and clog up the drainfield. If you have a hot tub, it would be best to drain it with a hose and onto a safe area outside of the septic system.
Toilet. Not only does the toilet bowl account for at least 30% of total water usage in the average household, but improper use of it can also cause problems for any septic system. As earlier learned, excess water flowing into the septic tank can overwhelm it and disrupt the processes inside. It is for this reason why you should consider switching to a low-flow toilet that can cut down water usage down to at least half. It is also absolutely vital that everyone in the home watches what are tossed in the toilet. Things like diapers, dental floss, feminine hygiene products, coffee grounds, and other non-organic substances can quickly clog the tank and require a thorough pumping and cleaning.
Garbage Disposal. Although garbage disposal units are a real convenience in the kitchen, it is not exactly friendly to the septic tank. As with the toilet, the wrong materials in the garbage disposal will cause major problems with your septic system. Just as excessive water volumes of water can be harmful to the septic system, an increase of solid waste, fat, grease, and biomass, entering the septic tank cause the it to fill up much faster than it can decompose it and, thus require more frequent pumping, at the very least. If you need to have a garbage disposal unit, do use it as sparingly as possible. And watch what you throw into it. But if it can be helped, diminish or eliminate the need for a garbage disposal unit by reducing waste through recycling or composting.
If you are sensible in your choice and use of dishwasher detergent, draining dishwasher discharge into a septic tank shouldn’t harm the natural bacterial and enzyme balance in your septic tank and field. It’s the possible flooding of the drainfield from dishwasher water that could wreak havoc on your system. This is why energy-efficient dishwasher machines are best. These use less water and less energy, too. Also, diverting dishwasher discharge into a drywell and away from your on-site waste treatment system is a good alternative. While newer septic systems are designed to handle increased water usage, countless homes and septic tanks from earlier years were not designed to handle such demands from modern appliances or fixtures. But being judicious in your dishwasher machine and equipment choices is only half the battle: keeping your septic system running as efficiently as possible with regular inspection, pumping, and maintenance by septic service professionals every 2-5 years is still key.