What is Greywater?

What is grey water

Last year’s severe drought was a wake up call for a lot of people in the Columbia area. The drought lasted over six months, from May 2019 through January 2020. During that time, the Midlands were under a burn ban and water use restrictions, depending on the severity of the drought in the area in which you live.

Need the most recent drought updates so that you can be prepared for using more greywater? Click here for a South Carolina drought coverage map.

Now that you have been faced with the challenges of a drought, you might be more ready to take water conservation seriously. One of the best ways to conserve water is to make use of cleaner water waste. Not all waste water is unsuitable for additional use. You can reuse water from your washing machine, dishwasher, or even bathing. There is a lot you should know about collecting and reusing greywater before you jump on the bandwagon. Here is what you need to know about the safety and use of greywater.

 in-home flooding is caused by broken pipes. Most people think of the potential for burst pipes only in the winter when you have to worry about pipes freezing.

What is greywater?

It can be really confusing to figure out what water waste is considered greywater and can be reused. It is extremely important that you know the appropriate sources of greywater and how to use them safely, both for your household and the environment in general.

Greywater is relatively clean waste water that can be used for other purposes, primarily lawn irrigation or watering plants. The most common sources of greywater include:

  • Water from bathtub or shower
  • Rinse water from your sinks
  • Rinse water from washing machines or dishwashers

Of course, the environmental impacts of greywater depend somewhat on the cleaners or soaps that are mixed into the waste water.

Grey water vs black water

It is very important that you understand the difference between greywater and black water. Black water is wastewater that cannot be reused or introduced to the groundwater for any reason. For the most part, this is going to be the water from flushing your toilet. If you are even in doubt as to whether your waste water can be recycled, assume the worst and dispose of it instead.

What can greywater be used for?

Greywater is suitable for use in both outdoor and indoor applications, but not enough to use all of the wastewater your household produces every day.

Even though you can use grey water for all of these purposes, you do need to use it intermittently with fresh water. You can use gray water for:

  • Irrigating the soil beneath your lawn
  • Watering fruit trees and some vegetables
  • Irrigating fire breaks
  • Watering some garden plants
  • Flushing toilets
  • Wash clothing, if the previous load was only lightly soiled

Of all of these, the two best water savers are to use grey water for flushing toilets and washing additional loads of laundry. Toilet flushing typically amounts to at least half of a family’s water usage. If you can flush your toilet with greywater, you’ll conserve quite a bit of fresh water. There are some safety caveats, discussed below.

Your drains can back up and pipes can burst due to sewer problems

Grey Water Safety Guidelines

Although grey water is useful for a lot of high consumption uses, it isn’t necessarily 100% safe. The state of South Carolina has regulations regarding how grey water can be collected, when and how it must be treated, how it can be used, and how it must be disposed of when no longer safe to use.

In general, you should follow these safety tips:

  • Never use greywater where it might touch something for human consumption (i.e. root vegetables or vegetables where the edible portion is exposed to the water)
  • Never pour grey water into the toilet tank. If you are using greywater to flush you must pump it directly into the toilet bowl.
  • Never use waste water from dish loads that include cooking utensils or pots and pans, because the oils and grease on them is harmful to the environment.
  • Greywater offers fertilization for established plants, but it can kill saplings, seedlings, and younger plants.
  • Untreated greywater should not be stored for more than 24 hours, treated greywater may or may not be able to store for slightly longer periods.

There are some additional guidelines that you must follow to be in compliance with the law. These regulations may include how your wastewater is collected, stored, and disposed of. It is best to have a professional and experienced plumber assess your systems and determine if these safety measures can be met, or if your home is not a candidate for a greywater plumbing system.

Greywater government regulations

South Carolina has very strict regulations about the collection and recycling of grey water. These regulations are meant to protect the public and environment from potentially harmful waste water use.

It would be impossible to list all of the South Carolina and Midlands greywater regulations within this space. The full codes for greywater in the area are listed online, but the most important for most homeowners are:
If you direct greywater to an outdoor outlet for irrigation, you must mark that outlet with specific wording and graphics.
If a grey water system and a fresh water system connect, there must be a backflow system in place to protect the clean water.
Any plumbing for greywater needs to be carefully protected against freezing, insects, vermin, and other hazards that can lead to leaks of greywater into the groundwater.

Most of the regulations regarding grey water usage in South Carolina will only apply if you are going to install plumbing to make the process easier and less time consuming. If you are only collecting greywater in buckets and using it to flush your toilets, you aren’t going to need to worry about any of these regulations.

Establishing a greywater collection, delivery, and disposal system

Before you can install plumbing for greywater recycling, you’ll need a permit, as well as inspections upon completion. Some experienced DIY homeowners may be able to install this plumbing system on their own, but most people are going to need at least a little bit of help deciphering the requirements that apply to them.

If you are serious about reducing your fresh water consumption, we are here to help you convert or add to your plumbing to make it possible. Recycling water doesn’t have to take a lot of effort, and with the right system, anyone can do it. Contact us today for an assessment to see if using greywater is the right move for you.


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