The 7 Best Laundry Detergents for Septic Systems of 2023

Best Overall

ECOS Liquid Laundry Detergent with Built-In Fabric Softener

4.6

View On Amazon View On Walmart

The ECOS Laundry Detergent is our top pick because it's biodegradable and safe to use in a variety of home water systems. We also love the light smell and effective cleaning power of its eco-friendly formula. This concentrated product comes in 100-ounce bottles that can be used for up to 100 loads of laundry, and its plant-powered formula has a wonderful magnolia and lily scent. Its formula is free from dyes, optical brighteners, parabens, phosphates, and phthalates, and it's hypoallergenic and pH-balanced for users with sensitive skin.

This laundry detergent also includes a built-in fabric softener to save you money, plus it works in all water temperatures and in both high-efficiency (HE) and standard washing machines. It's also certified as a U.S. EPA Safer Choice product, meaning it's made with ingredients that are safe for human health and the environment. ECOS is also a climate positive company, where all of their products are made in carbon neutral, water neutral, TRUE Platinum Zero Waste factories that use 100 percent renewable energy. So, you can not only feel good about using this detergent with a septic system, but you can also feel good about the impact your purchase makes on your personal and environmental health. How's that for a win-win?!

Overall, we think this detergent is not only a cost-efficient option, but it's also environmentally conscious and effective against tough stains and smells in your clothes.

Price at time of publish: $31/2-pack

Best Budget

Arm & Hammer Plus OxiClean Odor Blasters Laundry Detergent

View On Amazon View On Lowe's

Certain septic-safe detergents are quite expensive, but you can stick to your budget with the Arm & Hammer Plus OxiClean Odor Blasters Laundry Detergent. This popular household brand is specially formulated to break down body odors, sweat, and other tough scents, but its formula is still safe to use in your septic system.

This detergent comes in 122.5-ounce bottles that can be used for around 70 loads of laundry, and the formula is biodegradable, making it ideal for use in homes with septic systems. Arm & Hammer detergent contains OxiClean Stain Fighters that help to remove dirt and stains from clothing, and it’s a favorite among homeowners, thanks to its fresh smell and affordable price.

Price at time of publish: $10

Best Green

Seventh Generation Free & Clear Concentrated Laundry Detergent

4.8

View On Amazon View On Walmart

For a more eco-friendly detergent, you can’t go wrong with the Seventh Generation Free & Clear Unscented Concentrated Laundry Detergent. This top-rated formula comes in 40-ounce bottles that contain enough detergent for up to 53 loads or 100-ounce bottles that last for 66 loads, and as its name suggests, the detergent is hypoallergenic and fragrance-free, ensuring it doesn’t irritate sensitive skin.

What's so great about this product? Seventh Generation Detergent has a powerful triple-enzyme formula that effectively breaks down dirt and stains, and it’s actually both a USDA Certified Biobased Product and an EPA Safer Choice Certified Product. The cleaning solution is biodegradable and septic safe, and despite its gentle nature, we think a little bit of the plant-based formula goes a long way toward getting clothing clean.

Price at time of publish: $15

Best Unscented

Method Free + Clear Laundry Detergent

View On Target

If scented laundry detergents irritate your senses—or you just prefer not to have your clothes smelling floral—you’ll like the Method Free + Clear Laundry Detergent. This naturally derived formula is made without any dyes or fragrances, and it’s hypoallergenic, too, making it a great choice for anyone with sensitive skin.

Best of all, this high-efficiency detergent has no formaldehyde, parabens, chlorine, phosphates, phthalates, and DEA, yet it still removes dirt and stains, keeping colors bright and whites clear. The naturally derived detergent comes in 53.5-ounce bottles (made from recycled plastic), which you should be able to use for up to 66 loads of laundry. And, of course, the biodegradable formula is safe to use with septic systems, so you can rest easy knowing it won’t harm beneficial bacteria. 

Price at time of publish: $15

Best Concentrated

Solimo Concentrated Liquid Laundry Detergent

View On Amazon

Many laundry detergents are diluted with water, which means you have to use more product per cycle. But Solimo Concentrated Liquid Laundry Detergent is a septic-safe formula that hasn’t been watered down. In fact, you’ll be able to complete up to 128 loads of laundry using the affordable 96-ounce bottle.

This detergent is available in several scents, including lavender, clean linen, and unscented Free Clear. It’s compatible with both high-efficiency and standard washing machines, and the formula contains powerful stain fighters to leave your household's clothes squeaky clean after every wash! The concentrated detergent has twice as many loads per bottle versus a standard formula, and the brand even offers a money-back guarantee within a full year of purchase.

Price at time of publish: $18

Best Powder

Charlie's Soap Fragrance Free Laundry Powder

4.2

View On Amazon View On Home Depot View On Walmart

If you prefer powder laundry detergent to liquid products, one of the best septic-safe choices is Charlie’s Soap Laundry Powder. This eco-friendly formula comes in 2.64-pound bags that contain up to 100 loads of laundry.

Charlie’s Soap is made with powerful natural ingredients—in fact, there are just four ingredients used in the formula—and it’s biodegradable and free from artificial brighteners and perfumes. The powder detergent doesn’t create suds, making it better for aerated septic systems, yet it still effectively removes dirt, grease, and stains, leaving fabric fresh and soft.

Price at time of publish: $55