Should Greywater Go Into Septic Tank

This post may contain affiliate links. This means I will make a commission at no extra cost to you should you click through and make a purchase. Read the Affiliate Disclaimer and Privacy Policy.


Explore the best options for managing greywater, and learn whether it is safe to send greywater to a septic tank system.

What is greywater? Greywater is household or domestic wastewater from baths, showers, sinks, and laundry. Greywater typically contains fewer contaminants than sewage and is therefore considered to be less harmful to the environment when it is properly treated. In many parts of the world, greywater is recycled and used for irrigation or other non-potable purposes. There are various methods for treating and reusing greywater, including natural systems that rely on plants and bacteria to purify the water, as well as mechanical systems that use filters and other treatments to remove contaminants. It is important to follow local regulations and guidelines for greywater reuse, as the safety and suitability of greywater for reuse can vary depending on the source and the intended use.

Should Greywater Go Into Septic Tank

Septic systems are commonly used for domestic wastewater treatment in areas where a centralized sewage system or sewer system is not available. They consist of a septic tank and a drain field, and rely on anaerobic bacteria and natural processes to treat the wastewater. However, the microorganisms and chemicals present in greywater can affect the performance of septic systems and ultimately reduce their lifespan.

One of the main concerns with greywater is that it contains a high level of microbial and chemical contaminants, such as those found in household cleaning detergents and personal care products. These contaminants can inhibit the growth of the beneficial bacteria that are responsible for breaking down organic matter in the septic tank.

Greywater also reduces the system’s hydraulic retention time, which is the amount of time that wastewater is retained in the tank to allow for the decomposition of organic matter. When the hydraulic retention time is reduced, the effluent (treated wastewater) may be dirtier and have higher levels of pollutants, which can impact the quality of the receiving environment.

Related Post  Are Laundry Pods Safe For Septic System?

In addition to reducing the effectiveness of the septic tank, greywater can also cause clogging in the drain field, which is the part of the septic system where the treated wastewater is filtered as it seeps into the ground. The detergents and cleaning products present in greywater can clog the drain field, which can reduce the lifetime of the drain field and require more frequent maintenance.

Diversion of greywater to an irrigation system can be an effective way to avoid potential problems with the septic system, and also provide an additional source of water for landscaping.

Greywater filtration systems

Should Greywater Go Into Septic Tank

Greywater filtration systems can help to remove contaminants and solids from the greywater, making it safe for use on flowers, plants and lawns. This can be a cost-effective way to conserve water and reduce the load on a septic system. It is also important to ensure that the irrigation system is designed and installed correctly, in order to ensure that the greywater is distributed evenly and does not create any standing water or flooding. It is important to check if the local codes allow such a system before installing one.

Should Greywater Go Into Septic Tank: FAQs

Here is a list of Frequently Asked Questions about “Should Greywater Go Into Septic Tank”

Should bath water go into septic tank

It is generally safe to direct bathwater into a septic tank system for treatment and disposal. However, it’s important to be mindful of the potential impact that bathwater can have on a septic system. Bathwater, like other forms of greywater, may contain hair, soap, and other contaminants that can clog the septic system. Additionally, high amounts of bathwater, can kill the anaerobic bacteria that are responsible for breaking down the waste in the septic tank. If you have a high use of bathwater it could overload the septic tank and the leach field making it fail.

Related Post  How do you do laundry with a septic system?

It is a good idea to spread the use of water through the day instead of having a high peak use all at once. Regular maintenance of the septic system, such as pumping the tank and cleaning the filters, can also help to mitigate the impact of bathwater on the septic system.

Does shower water go into septic tank

Yes, shower water is directed into a septic tank system via drains for treatment and disposal. The septic tank is designed to treat and break down the solids and liquids that enter the system. However, similar to bathwater, shower water may contain hair, soap, and other contaminants that can clog the septic system. It’s important to make sure that shower water is not overloading the septic tank by spacing out the use of shower, limiting the use of exfoliants or chemical products in the shower.

Does Laundry affect the septic system

When doing laundry with a septic system, it’s important to be mindful of the impact that greywater from the laundry can have on the system. Here are some tips ‘How do you do laundry with a septic system’:

  1. Spread out laundry loads throughout the week to prevent high peak use.
  2. Use a front-loading washing machine, which typically uses less water than a top-loading machine.
  3. Using liquid detergents instead of powdered detergents can be beneficial for septic systems. Liquid detergents are more easily broken down by the anaerobic bacteria in the septic tank that are responsible for breaking down the waste. They also don’t have the non-soluble fillers or the possibility of over-dosing like powder detergents do. Additionally, liquid detergents are more readily soluble in water and don’t leave behind undissolved particles, which can clog the system or even affect the performance of the leach field.
  4. Avoid using harsh chemicals or bleach when washing clothes, as these can harm the bacteria in the septic tank that break down waste.
  5. Consider using a greywater filter system to remove contaminants and solids from the greywater before it enters the septic system.
  6. Use of a high-efficiency detergent that requires less water to use
Related Post  How Often Can You Do Laundry With A Septic System

Laundry detergents

The best laundry detergent for septic systems are those that are labeled as “septic-safe” and do not contain harmful chemicals or ingredients that can damage the septic system. Some recommended options include:

  • Seventh Generation Liquid Laundry Detergent
  • ECOS Liquid Laundry Detergent
  • Rockin’ Green Classic Rock Laundry Detergent
  • BioKleen Laundry Liquid
  • Method 4X Concentrated Laundry Detergent

It’s important to note that even septic safe laundry detergents can be harmful in large amounts, so it’s important to follow the recommended usage instructions.

Final Thoughts

In conclusion, greywater can have a significant impact on septic systems if not properly treated. Greywater contains a high level of microbial and chemical contaminants, which can inhibit the growth of beneficial bacteria in septic tanks, reduce the hydraulic retention time, and result in dirtier effluent and reduced lifetime of the drain field. To mitigate these issues, greywater should be properly treated before it enters the septic system. This can involve using mechanical or natural treatment systems, or separating greywater from blackwater. Proper treatment and management of greywater can help to protect the environment and prolong the lifespan of septic systems.