… Such tensions were on display this week when the State Environmental Protection Agency threatened to close scores of plants, some run by powerful state companies, unless they complied with pollution rules. Sepa is a relatively weak agency that struggles to enforce its writ in large parts of the country but has in the past used publicity to publicise offenders to bring them to heel. Its campaign may already be having an impact, with Datang International Power Generation, one of the country’s largest power producers, announcing yesterday it would begin to close five 50 megawatt coal-fired stations in Tangshan, a steelmaking centre near Beijing.