8071
This has led to a great improvement in ammonia levels and BOD , further aided by the construction of biological treatment facilities for the processing of industrial effluent in the Doncaster area , while the decline in the steel industry in Sheffield has reduced the discharge of metals into the river .
 location: Doncaster; location: Sheffield
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 location: Doncaster; location: Sheffield