Risky reservoirs: Massachusetts counties where aging dams pose the greatest threat

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- Total high-hazard dams: 41
- Number potentially dangerous: 3 (7.3%)
- Potentially dangerous dams include:
--- 1 posing immediate threat
--- 2 in poor condition

#9. Berkshire County
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- Total high-hazard dams: 19
- Number potentially dangerous: 2 (10.5%)
- Potentially dangerous dams include:
--- 2 condition withheld

#8. Hampshire County
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- Total high-hazard dams: 24
- Number potentially dangerous: 3 (12.5%)
- Potentially dangerous dams include:
--- 3 condition withheld

#7. Hampden County
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- Total high-hazard dams: 42
- Number potentially dangerous: 6 (14.3%)
- Potentially dangerous dams include:
--- 1 posing immediate threat
--- 5 in poor condition

#6. Middlesex County
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- Total high-hazard dams: 18
- Number potentially dangerous: 3 (16.7%)
- Potentially dangerous dams include:
--- 1 posing immediate threat
--- 1 in poor condition
--- 1 not rated

#5. Norfolk County
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- Total high-hazard dams: 23
- Number potentially dangerous: 4 (17.4%)
- Potentially dangerous dams include:
--- 1 posing immediate threat
--- 3 in poor condition

#4. Bristol County
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- Total high-hazard dams: 34
- Number potentially dangerous: 6 (17.6%)
- Potentially dangerous dams include:
--- 6 in poor condition

#3. Essex County
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- Total high-hazard dams: 100
- Number potentially dangerous: 22 (22.0%)
- Potentially dangerous dams include:
--- 2 posing immediate threat
--- 4 in poor condition
--- 16 condition withheld

#2. Worcester County
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- Total high-hazard dams: 10
- Number potentially dangerous: 4 (40.0%)
- Potentially dangerous dams include:
--- 1 posing immediate threat
--- 3 in poor condition

This story features data reporting by Paxtyn Merten, writing by Dom DiFurio, and is part of a series utilizing data automation across 50 states.

#1. Plymouth County
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