Most private well owners, however, have been forced to test and treat their own water for these chemicals. The average cost to test a well for forever chemicals is $300, according to public health advocates. The standard, which goes into effect in 2029, applies only to public water, not private wells. The lawsuit seeks to recover the cost of cleaning up forever chemicals. Forever chemicals have been used since the 1940s in consumer products and industry, including in nonstick pans, food packaging and firefighting foam.