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Dimension Stone, Westford, Massachusetts. NPDES permit MA0020231, in force until Aug 31, 2030. Last 12 months: no values over a limit. Source: EPA ECHO, Oct 22, 2026.
| Parameter | Statistic | Limit | Months |
|---|---|---|---|
| Temperature, water deg. centigrade | daily maximum | report only (deg C) | Jul–Dec |
| Flow rate | instantaneous maximum | report only (gal/min) | all year |
| Turbidity | monthly average | ≤ 25 NTU | all year |
| Turbidity | daily maximum | ≤ 25 NTU | all year |
| pH | minimum | ≥ 6.5 SU | all year |
| pH | maximum | ≤ 8.3 SU | all year |
| pH | daily maximum | report only (SU) | Jul–Dec |
| Solids, total suspended | monthly average | ≤ 20 mg/L | all year |
| Solids, total suspended | daily maximum | ≤ 40 mg/L | all year |
| Oil & Grease | daily maximum | report only (mg/L) | all year |
| Nitrogen, total [as N] | daily maximum | report only (mg/L) | all year |
| Nitrogen, ammonia total [as N] | daily maximum | report only (mg/L) | all year |
| Nitrogen, ammonia total [as N] | daily maximum | report only (mg/L) | Jul–Dec |
| Nitrogen, ammonia total [as N] | daily maximum | report only (mg/L) | Jul–Dec |
| Hardness, total [as CaCO3] | daily maximum | report only (mg/L) | Jul–Dec |
| Hardness, total [as CaCO3] | daily maximum | report only (mg/L) | Jul–Dec |
| Cadmium, total [as Cd] | daily maximum | report only (mg/L) | Jul–Dec |
| Cadmium, total [as Cd] | daily maximum | report only (mg/L) | Jul–Dec |
| Copper, total [as Cu] | daily maximum | report only (mg/L) | Jul–Dec |
| Copper, total [as Cu] | daily maximum | report only (mg/L) | Jul–Dec |
| Lead, total [as Pb] | daily maximum | report only (mg/L) | Jul–Dec |
| Lead, total [as Pb] | daily maximum | report only (mg/L) | Jul–Dec |
| Nickel, total [as Ni] | daily maximum | report only (mg/L) | Jul–Dec |
| Nickel, total [as Ni] | daily maximum | report only (mg/L) | Jul–Dec |
| Zinc, total [as Zn] | daily maximum | report only (mg/L) | Jul–Dec |
| Zinc, total [as Zn] | daily maximum | report only (mg/L) | Jul–Dec |
| Aluminum, total [as Al] | daily maximum | report only (mg/L) | Jul–Dec |
| Aluminum, total [as Al] | daily maximum | report only (mg/L) | Jul–Dec |
| Days per Month | total | report only (d/mo) | all year |
| Perchlorate [ClO4] | daily maximum | report only (mg/L) | all year |
| Flow, total | monthly total | report only (gal/mo) | all year |
| LC50 Static 48Hr Acute Ceriodaphnia dubia | minimum | report only (%) | Jul–Dec |
| LC50 Static Renewal 48Hr Acute Pimephales promelas | minimum | report only (%) | Jul–Dec |
Cited limits by parameter: Massachusetts's rules and the federal ones.
Same industry: the 4 Mining and Quarrying of Nonmetallic Minerals permits in Massachusetts.
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On EPA ECHO: Facility report · DMR history
Your permit document is the final word. As JSON: /api/v1/permits/MA0020231 · MCP: https://passage-data.com/mcp