BROOKINGS — Mayor Pat Sherman and U.S. Borax expect to sign a formal cost-sharing agreement for the remaining offsite infrastructure needs related to the development of Lone Ranch, a 182-acre planned community of 1,000 residences. The city already has spent $794,000 on a sewer expansion project serving the area and wants to make sure Borax shares in any additional future costs. Development of the community is expected to begin next year. Burton Weast, a Borax spokesman, says Borax also will donate a 10-acre parcel to the Southwestern Oregon Community College. Borax has owned Lone Ranch for more than 100 years.