Environmental monitoring for the 2025 construction includes water and air. Air monitoring is performed around the Route 131 Staging Area. Water monitoring is performed in the river and at water intakes. These monitoring activities and results are summarized below.
Air Monitoring - 2025 Route 131 Staging Area
Program includes particulate monitoring using real-time meters for particulates (or dust). A corrective action level was established based on levels that are safe for the community. The actual monitoring results are compared to the corrective action levels to determine if adjustments in construction are needed. The air monitoring locations and tabulated results are provided below.
Air Monitoring Locations - Rt 131 Staging Area
2025 Air Particulate Data (Corrective Action Level = 0.150 milligram per cubic meter above upwind location)
| Monitoring Station ID (see figure) | ||||||
|---|---|---|---|---|---|---|
| Date | Action Level Check | SA-AIR1 | SA-AIR2 | SA-AIR3 | SA-AIR4 | Notes |
| April 29 | All Below | 0.006 | 0.0028 | 0.0107 | 0.0523 | -- |
| April 30 | All Below | 0.0201 | 0.0237 | 0.0255 | 0.0536 | -- |
| May 1 | All Below | 0.0108 | 0.0111 | 0 | 0.053 | SA-AIR3 data not available, unit verified in field and no exceedances observed |
| May 2 | All Below | 0.015 | 0.0119 | 0.0207 | 0.0043 | -- |
| May 3 | All Below | 0.0173 | 0.0171 | 0.0229 | 0.0517 | -- |
| May 4 | All Below | 0.0073 | 0.028 | 0.0127 | 0.034 | -- |
| May 5 | All Below | 0.0084 | 0.0098 | 0.0086 | 0.0185 | -- |
| May 6 | All Below | 0.0043 | 0.0086 | 0.0146 | 0.002 | -- |
| May 7 | All Below | 0.0053 | 0.0104 | 0.0107 | 0.0521 | -- |
| May 8 | All Below | 0.0071 | 0.0092 | 0.0169 | 0.045 | -- |
| May 9 | All Below | 0.0182 | 0.0211 | 0.0285 | 0.0768 | -- |
| May 10 | All Below | 0.0118 | 0.0143 | 0.0203 | 0.0207 | -- |
| May 11 | All Below | 0.0058 | 0.0094 | 0.0155 | 0.0558 | -- |
| May 12 | All Below | 0.0084 | 0.0103 | 0.0131 | 0.0057 | -- |
| May 13 | All Below | 0.008 | 0.0121 | 0.0174 | 0.0555 | -- |
| May 14 | All Below | 0.0161 | 0.0169 | 0.0237 | 3.5681 | SA-AIR4 elevated reading due to meter error. No exceedances or visible dust observed in the field. |
| May 15 | All Below | 0.0142 | 0.0286 | 0.0224 | 2.9068 | SA-AIR4 elevated reading due to meter error. No exceedances or visible dust observed in the field. |
| May 16 | All Below | 0.055 | 0.0541 | 0.1045 | 0.0821 | SA-AIR3 elevated reading due to fog. No exceedances or visible dust observed in the field. |
| May 17 | All Below | 0.0224 | 0.0331 | 0.0377 | 0.0212 | -- |
| May 18 | All Below | 0.0081 | 0.0188 | 0.023 | 0.0387 | -- |
| May 19 | All Below | 0.0054 | 0.012 | 0.0104 | 0.0341 | -- |
| May 20 | All Below | 0.003 | 0.0763 | 0.0053 | 0.0418 | -- |
| May 21 | All Below | 0.016 | 0.0125 | 0.1087 | 0.0175 | SA-AIR3 elevated reading due to equipment error. No exceedances or visible dust observed in the field. |
| May 22 | All Below | 0.0074 | 0.0131 | 0.1048 | 0.0242 | SA-AIR3 elevated reading due to equipment error. No exceedances or visible dust observed in the field. |
| May 29 | All Below | 0.0282 | 0.0219 | 0.1142 | 327.259 | SA-AIR3 elevated reading due to humidity at the site. No exceedances or visible dust observed in the field. SA-AIR4 elevated reading due to equipment error at the site. No exceedances or visible dust observed in the field. |
| May 30 | All Below | 0.0108 | 0.0138 | 0.0248 | 0 | SA-AIR4 is not operational. Replacement equipment has been ordered. |
| May 31 | All Below | 0.02 | 0.0217 | 0.0338 | 0.0244 | -- |
| June 1 | All Below | 0.0215 | 0.0238 | 0.3766 | 0.1419 | SA-AIR4 elevated reading for 15 minutes. SA-AIR3 elevated reading possibly due to rain. Levels resolved on their own. |
| June 2 | All Below | 0.0078 | 0.0041 | 0.0209 | 0.0106 | -- |
| June 3 | All Below | 0.0065 | 0.0158 | 0.0197 | 0.246 | -- |
Particulates (milligrams per cubic meter)
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Water Monitoring - 2025 River and Intakes
Program includes turbidity monitoring using real-time meters for solids at the water intake locations and total suspended solids (TSS) at the river locations. Corrective action levels were established based on levels that were safe for the community. The actual monitoring results are compared to the corrective action levels to determine if adjustments in construction are needed. Monitoring also includes PCBs in the river for 10 days at the beginning of construction. The water locations and tabulated results are provided below.
Water Column Monitoring Locations
2025 Water Column Total Suspended Solids Data (Corrective Action Level = 100 mg/L above WC-UP Level at WC-SLR)
| Monitoring Station ID (see figure) | ||||||
|---|---|---|---|---|---|---|
| Date | Action Level Check | WC-UP | WC-NF | WC-MOUTH | WC-SLR | Notes |
| April 28 | All Below | 12 | 5.4 | Below detectable levels | Below detectable levels | -- |
| April 29 | All Below | 12 | 7.6 | 5.1 | Below detectable levels | -- |
| April 30 | All Below | 7.6 | 8.1 | 6.7 | Below detectable levels | -- |
| May 1 | All Below | Below detectable levels | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| May 2 | All Below | Below detectable levels | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| May 3 | All Below | Below detectable levels | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| May 5 | All Below | Below detectable levels | 6.7 | Below detectable levels | Below detectable levels | -- |
| May 6 | All Below | Below detectable levels | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| May 7 | All Below | Below detectable levels | 5.5 | Below detectable levels | Below detectable levels | -- |
| May 8 | All Below | Below detectable levels | 13 | Below detectable levels | Below detectable levels | -- |
| May 9 | All Below | Below detectable levels | 5.4 | 5.5 | Below detectable levels | -- |
| May 10 | All Below | Below detectable levels | 13 | Below detectable levels | Below detectable levels | -- |
| May 12 | All Below | Below detectable levels | Below detectible levels | Below detectable levels | Below detectable levels | -- |
| May 13 | All Below | Below detectable levels | 12 | 5.1 | Below detectable levels | -- |
| May 14 | All Below | Below detectable levels | 5.1 | Below detectable levels | Below detectable levels | -- |
| May 16 | All Below | Below detectable levels | Below detectible levels | Below detectable levels | Below detectable levels | -- |
| May 17 | All Below | 5.4 | 5.8 | Below detectable levels | Below detectable levels | -- |
| May 19 | All Below | Below detectable levels | 8.1 | Below detectable levels | Below detectable levels | -- |
| May 20 | All Below | 5.1 | 5.9 | 5.7 | Below detectable levels | -- |
| May 21 | All Below | Below detectable levels | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| May 28 | All Below | Below detectable levels | 5.1 | Below detectable levels | Below detectable levels | -- |
| May 29 | All Below | Below detectable levels | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| May 30 | All Below | Below detectable levels | 6.8 | Below detectable levels | Below detectable levels | -- |
Total Suspended Solids (TSS; milligrams per liter)
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2025 Water Column PCB Data (Corrective Action Level at WC-SLR = 0.5 microgram per liter)
| Monitoring Station ID (see figure) | |||||
|---|---|---|---|---|---|
| Date | Action Level Check | WC-NF | WC-MOUTH | WC-SLR | Notes |
| April 28 | All Below | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| April 29 | All Below | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| April 30 | All Below | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| May 1 | All Below | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| May 2 | All Below | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| May 3 | All Below | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| May 5 | All below | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| May 6 | All below | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| May 7 | All below | Below detectable levels | Below detectable levels | Below detectable levels | -- |
| May 8 | All below | Below detectable levels | Below detectable levels | Below detectable levels | -- |
Particulates (milligrams per cubic meter)
Total PCBs (micrograms per liter)
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Water Intake Monitoring Locations
2025 Water Intake Turbidity Data (Corrective Action Level = 25 NTU above Baseline Level)
| Monitoring Station ID (see figure) | |||||
|---|---|---|---|---|---|
| Date | Action Level Check | IN-AE-RAW | IN-SRMT-RAW | IN-SRMT-FIL | Notes |
| April 28 | All Below | 1.0 | 2.0 | 0.9 | -- |
| April 29 | All Below | 0.7 | 0.9 | 0.4 | -- |
| April 30 | All Below | 0.7 | 1.5 | 0.4 | -- |
| May 1 | All Below | 1.4 | 1.0 | 0.5 | -- |
| May 2 | All Below | 1.6 | 1.3 | 0.4 | -- |
| May 3 | All Below | 1.4 | 1.2 | 1.1 | -- |
| May 5 | All Below | 1.0 | 0.3 | 0.3 | -- |
| May 6 | All Below | 1.3 | 0.8 | 0.5 | -- |
| May 7 | All Below | 0.6 | 1.0 | 0.2 | -- |
| May 8 | All Below | 0.7 | 1.0 | 0.4 | -- |
| May 9 | All Below | 1.6 | 1.0 | 0.5 | -- |
| May 10 | All Below | 0.4 | 0.9 | 0.7 | -- |
| May 12 | All Below | 1.1 | 0.9 | 0.5 | -- |
| May 13 | All Below | 1.2 | 0.7 | 0.1 | -- |
| May 14 | All Below | 1.1 | 0.5 | 0.1 | -- |
| May 15 | All Below | 0.8 | 0.9 | 0.1 | -- |
| May 16 | All Below | 0.9 | 0.4 | 0.3 | -- |
| May 17 | All Below | 1.1 | 0.8 | 0.4 | -- |
| May 19 | All Below | 1.4 | 1.1 | 0.5 | -- |
| May 20 | All Below | 1.0 | 0.2 | 0.1 | -- |
| May 21 | All Below | 1.1 | 0.6 | 0.1 | -- |
| May 28 | All Below | 0.9 | 0.6 | 0.2 | -- |
| May 29 | All Below | 1.1 | 0.7 | 0.6 | -- |
| May 30 | All Below | 1.3 | 1.7 | 0.3 | -- |
| May 31 | All Below | 1.4 | 0.9 | 0.6 | -- |
| June 1 | All Below | 1.0 | 0.8 | 0.1 | -- |
| June 2 | All Below | 1.3 | 1.0 | 0.1 | -- |
Turbidity (Nephelometric Turbidity Unit)
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