I don't know if this is "good" or "bad" for the environment, but it works for the cheap-skate in me. I started making my own laundry detergent and it now costs us pennies for huge batches. The initial cost of a box of borax and a box of Arm and Hammer Super Washing Soda was about $15, but those two boxes will last 6 months to a year. All I have to buy now for many months will be a new Fels Naptha bar each time I make it. I just bought a new bar, and I believe it was $1.39. Each batch makes two laundry size jugs of liquid detergent. Since I have a front-loading machine, I only use 1/4 cup of the liquid homemade detergent.
Those of you with allergies to soaps - I know they make allergen-free recipes. Just google them, or look them up on Pinterest.