This paper from Stanford University's Understanding Language initiative discusses challenges and opportunities expected as ELLs engage with Next Generation Science Standards (NGSS). The authors describe intersections between science practices and language learning, features of science language and "science talk," and five areas where teachers can strengthen science and language learning for ELLs: literacy strategies with all students; language support strategies; discourse strategies with ELLs; home language support; and home culture connections.
Lee, O., Quinn, H., & Valdes, G. (2012). Language Demands and Opportunities in Relation to Next Generation Science Standards for English Language Learners: What Teachers Need to Know. Understanding Language: Stanford University School of Education.