Grey Water Soaps, Part 2

Guide to Grey water-Compatible Cleaning Products 

Wastewater that is discharged to the greywater system ends up in the garden soil and can either be beneficial or harmful to soil, water systems, and plant life. A common problem with improper use of greywater systems is salt build up in the soil which is hard to remedy and will negatively affect plant health. Toxic discharge, such as paints, hair dyes, or harsh cleaners, should never enter the greywater system, and should instead be routed through the municipal sewer. These substances can not only kill plants, they can also kill soil life and water life and persistently remain in soil. The greywater system should have a three-way valve, which allows wastewater to be routed back through the sewer as needed.

Note: water from the kitchen sink and toilet are considered blackwater, not greywater, and should not be recycled in the yard, but should be sent through the sewer system. Shower and bathtub water, however, are considered greywater, so greywater-friendly cleaning products should be used for cleaning shower and tub.

The effect of certain cleaning product ingredients depends in part on what type of greywater system is in place. If the greywater is going into the soil through a mulch basin (“terrestrial”), Nitrogen (N) and Phosphorus (P) ingredients are not a problem and in fact end up as soil nutrients. This is the case for the “laundry-to-landscape” type system. If the greywater is passing through a freshwater wetland (“aquatic”), however, N + P can lead to harmful algae growth and should be avoided. Conversely, Sodium (Na) is much more harmful to soil health than it is to a wetland system. A detailed chart of these variables can be found in Art Ludwig’s book Create an Oasis with Greywater.

Seek out cleaning products which are “biocompatible” or “biodegradable”.

Nitrogen (N), Phosphorus (P), Potassium (K), and Sulfur (S) are okay for greywater going directly into the soil / mulch basin.

Ingredients to Avoid:

  • boron/borax (toxic to plants)
  • sodium and ingredients with the word “sodium” in them*
  • chlorine bleach (acceptable alternative: hydrogen peroxide)
  • sodium perborate
  • sodium hypochlorite
  • peroxygen
  • petroleum distillate
  • alkylbenzene
  • water softeners (contain sodium chloride or potassium chloride)
  • anti-bacterial soaps & cleaners
  • “whiteners”, “softeners”
  • enzymes (enzymes in biological washing powders break down protein or fat stains on clothes)
  • titanium oxide
  • chromium oxide
  • artificial colors; FD&C colors
  • synthetic fragrance
  • artificial preservatives

*Note: Rainfall can help reduce salt build-up in soil, it is however advised to keep sodium out of greywater whenever possible.

Tip: liquid soaps tend to contain less sodium than powdered soaps — lean toward liquid laundry products.

Here are some examples of more- and less-suitable cleaning products for use with greywater systems:

1. Laundry Detergents — Liquid:

Recommended:

  • Earth Sap Range
  • PnP Green Range
  • Enchantrix Range

Limit:

Other Laundry Products:

Avoid:

Limit:

2. Body Soaps & Shampoos:

Recommended:

  • Pure Beginnings range
  • Oh Lief range
  • Enchantrix range

Avoid:

  • Dial liquid handsoap (sodium laureth sulfate, sodium chloride, antibacterial agent, cocamidopropyl betaine (synthetic surfactant),

Note: The Skin Deep database can help you find out what chemicals are in your body & beauty products.

3. Household Cleaners / Dish Soap / All Purpose Liquid Cleaner:

Recommended:

  • Earth Sap
  • PnP Green range
  • Enchantrix

Limit:

Avoid:

  • Ajax (sodium carbonate, bleach, fragrance, color);
  • Comet (bleach, +?);
  • Ajax (?);
  • Ivory (?);
  • Palmolive (?);
  • Joy (?);
  • Dawn (?)

Further Reading:

| Extracts from www.ecologycenter.org

Water Rhapsody Atlantic