Editing Turbidity (section)

===Drinking water standards===
Governments have set standards on the allowable turbidity in drinking water. In the United States, [[public water system]]s that use conventional or direct filtration methods must not have a turbidity higher than 1.0 NTU at the plant outlet and all samples for turbidity must be less than or equal to 0.3 NTU for at least 95 percent of the samples in any month. Systems that use filtration other than the conventional or direct filtration must follow state limits, which must include turbidity at no time exceeding 5 NTU. Many drinking water utilities strive to achieve levels as low as 0.1 NTU.<ref>{{cite web |title=National Primary Drinking Water Regulations |url=https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations |date=2022-01-26 |publisher=EPA}}</ref> The European turbidity standard is 4 NTU.<ref>{{cite web |title=What are the drinking water standards? |url=http://dwi.defra.gov.uk/consumers/advice-leaflets/standards.pdf |date=June 2017 |publisher=Drinking Water Inspectorate (UK) |location=London |archive-url=https://web.archive.org/web/20201111190539/http://dwi.defra.gov.uk/consumers/advice-leaflets/standards.pdf |archive-date=2020-11-11}}</ref>