Sentence:  study methods for the recovery and marketing of commercially valuable byproducts resulting from the conversion of saline water ; and undertake economic studies and surveys to determine present and prospective costs of producing water for <WSD>beneficial</WSD> consumptive purposes in various parts of the United States by the leading saline water processes as compared with other standard methods . 
Meaning of the word marked with <WSD> tags:  promoting or enhancing well-being