Question: who is responsible for enforcing water quality standards
[{'answer': 'U.S. Environmental Protection Agency', 'provenance': [{'wikipedia_id': '647655', 'title': 'Clean Water Act', 'start_paragraph_id': 1, 'start_character': 646, 'end_paragraph_id': 1, 'end_character': 682, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '647655', 'title': 'Clean Water Act', 'start_paragraph_id': 1, 'start_character': 4, 'end_paragraph_id': 1, 'end_character': 845, 'bleu_score': 0.8475785730151341, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6547488790211105471}, 'section': 'Section::::Abstract.'}]}]