22.0.2. The person in charge of a municipal distribution system serving more than 500 persons and at least one residence with water that originates in whole or in part from surface water must, for the purposes of controlling the total phosphorus, take or cause to be taken at least one sample of raw surface water during the period from May to October, with at least a 2-week interval between each sampling.
That person must also install a device to continuously measure the turbidity of raw water and take turbidity measurements and keep a record for that purpose. The provisions provided for in the fourth paragraph of section 22 apply, by making the necessary modifications to the provisions for taking measurements in the record.
If the water of more than one surface water withdrawal site gets mixed in the treatment facility, the obligations in the first and second paragraphs of this section apply to each of the withdrawal sites.