Quick Answer
Soaps safe for greywater irrigation are typically those that are free of or have low concentrations of phosphates, nitrates, and other contaminants. Biodegradable soaps, like those containing plant-based ingredients, are generally considered safe. Look for certifications like EPA Safer Choice or Greenguard Gold.
Choosing the Right Soap
When selecting a soap for greywater irrigation, it’s essential to consider the ingredients and potential impact on the environment. Phosphates and nitrates can contribute to algal blooms and eutrophication in waterways, making them a concern for greywater systems. Opt for soaps that are labeled as “biodegradable” or “non-toxic,” and aim to find products with a high percentage of plant-based ingredients, such as coconut oil, olive oil, or jojoba oil.
Understanding Soap Concentration
The concentration of soap in greywater can directly impact its safety for irrigation. A general rule of thumb is to use no more than 1-2% soap concentration in the greywater system. This translates to approximately 1-2 ounces of soap per 50 gallons of greywater. Exceeding this concentration can lead to soap scum buildup, clogged pipes, and potentially harm plants.
Certifications and Labels
When shopping for soaps, look for certifications like EPA Safer Choice or Greenguard Gold, which indicate that the product meets certain standards for safety and sustainability. These labels can provide an added layer of assurance that the soap is suitable for greywater irrigation. Additionally, check the ingredient list for any red flags, such as harsh chemicals or artificial fragrances, which may be detrimental to the environment or your plants.
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