Question: how many wastewater treatment plants are there in the us
[{'answer': 'over 16,000', 'provenance': [{'wikipedia_id': '24767927', 'title': 'Publicly owned treatment works', 'start_paragraph_id': 3, 'start_character': 10, 'end_paragraph_id': 3, 'end_character': 21, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '24767927', 'title': 'Publicly owned treatment works', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 282, 'bleu_score': 0.814568309231332, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2359608221775427262}, 'section': 'Section::::Abstract.'}]}]