Question: when was the original clean water act passed into law
[{'answer': '1948', 'provenance': [{'wikipedia_id': '647655', 'title': 'Clean Water Act', 'start_paragraph_id': 2, 'start_character': 108, 'end_paragraph_id': 2, 'end_character': 112, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '647655', 'title': 'Clean Water Act', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 401, 'bleu_score': 0.970362113628587, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14153933452440110218}, 'section': 'Section::::Abstract.'}]}]