WALDEN (V) STP
NPDES ID: NY0030490
E — SNC: Effluent violation (monthly average limit)
The facility discharged more of a pollutant than its permit allows, based on a monthly average.
This quarter: 4 effluent violations, 2 compliance schedule violations.
Violations
May 31, 2026
Nitrogen, ammonia total [as N]
442% over limit
Discharged 13 mg/L against a permitted limit of 2.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
493% over limit
Discharged 64.55879946 kg/d against a permitted limit of 10.89599991 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Flow, in conduit or thru treatment plant
8% over limit
Discharged 1.3 MGD against a permitted limit of 1.2 MGD (MO AVG)
DMR, Limited - Numeric Violation
April 30, 2026
Flow, in conduit or thru treatment plant
17% over limit
Discharged 1.4 MGD against a permitted limit of 1.2 MGD (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2026
Flow, in conduit or thru treatment plant
125% over limit
Discharged 2.7 MGD against a permitted limit of 1.2 MGD (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
105% over limit
Discharged 232.31179805 kg/d against a permitted limit of 113.49999905 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
70% over limit
Discharged 308.22059741 kg/d against a permitted limit of 181.59999847 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
5% over limit
Discharged 143.0099988 kg/d against a permitted limit of 136.19999886 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
10% over limit
Discharged 225.27479811 kg/d against a permitted limit of 204.29999828 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
February 28, 2026
BOD, carbonaceous [5 day, 20 C]
66% over limit
Discharged 41.5 mg/L against a permitted limit of 25 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
34% over limit
Discharged 53.4 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
53% over limit
Discharged 173.29179854 kg/d against a permitted limit of 113.49999905 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
13% over limit
Discharged 205.79819827 kg/d against a permitted limit of 181.59999847 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
January 31, 2026
Carbonaceous oxygen demand, % removal
25% over limit
Discharged 81.2 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
19% over limit
Discharged 29.7 mg/L against a permitted limit of 25 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
11% over limit
Discharged 44.5 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
October 31, 2025
Nitrogen, ammonia total [as N]
633% over limit
Discharged 17.6 mg/L against a permitted limit of 2.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen demand, ultimate
7% over limit
Discharged 85.3 mg/L against a permitted limit of 80 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
404% over limit
Discharged 54.93399954 kg/d against a permitted limit of 10.89599991 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2025
Nitrogen, ammonia total [as N]
575% over limit
Discharged 16.2 mg/L against a permitted limit of 2.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
416% over limit
Discharged 56.25059953 kg/d against a permitted limit of 10.89599991 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2025
Nitrogen, ammonia total [as N]
937% over limit
Discharged 112.95519905 kg/d against a permitted limit of 10.89599991 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
600% over limit
Discharged 16.8 mg/L against a permitted limit of 2.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
July 31, 2025
Flow, in conduit or thru treatment plant
8% over limit
Discharged 1.3 MGD against a permitted limit of 1.2 MGD (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
83% over limit
Discharged 19.97599983 kg/d against a permitted limit of 10.89599991 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
267% over limit
Discharged 8.8 mg/L against a permitted limit of 2.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
June 30, 2025
Nitrogen, ammonia total [as N]
471% over limit
Discharged 62.24339948 kg/d against a permitted limit of 10.89599991 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
233% over limit
Discharged 8 mg/L against a permitted limit of 2.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Flow, in conduit or thru treatment plant
67% over limit
Discharged 2 MGD against a permitted limit of 1.2 MGD (MO AVG)
DMR, Limited - Numeric Violation
May 31, 2025
Nitrogen, ammonia total [as N]
142% over limit
Discharged 5.8 mg/L against a permitted limit of 2.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
235% over limit
Discharged 36.50159969 kg/d against a permitted limit of 10.89599991 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Flow, in conduit or thru treatment plant
92% over limit
Discharged 2.3 MGD against a permitted limit of 1.2 MGD (MO AVG)
DMR, Limited - Numeric Violation
April 30, 2025
Flow, in conduit or thru treatment plant
50% over limit
Discharged 1.8 MGD against a permitted limit of 1.2 MGD (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
20% over limit
Discharged 136.65399885 kg/d against a permitted limit of 113.49999905 kg/d (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2025
Solids, total suspended
4% over limit
Discharged 212.88059821 kg/d against a permitted limit of 204.29999828 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
19% over limit
Discharged 161.53319864 kg/d against a permitted limit of 136.19999886 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
45% over limit
Discharged 262.95679779 kg/d against a permitted limit of 181.59999847 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
Carbonaceous oxygen demand, % removal
57% over limit
Discharged 76.4 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
Flow, in conduit or thru treatment plant
25% over limit
Discharged 1.5 MGD against a permitted limit of 1.2 MGD (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
65% over limit
Discharged 187.50199842 kg/d against a permitted limit of 113.49999905 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
29% over limit
Discharged 32.2 mg/L against a permitted limit of 25 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2025
Cadmium, total [as Cd]
0% over limit
Discharged 0.001 mg/L against a permitted limit of 0.025 mg/L (DAILY MX)
DMR, Limited - Overdue
Copper, total [as Cu]
0% over limit
Discharged 0.21792 kg/d against a permitted limit of 0.33596 kg/d (DAILY MX)
DMR, Limited - Overdue
Cadmium, total [as Cd]
0% over limit
Discharged 0.00454 kg/d against a permitted limit of 0.1135 kg/d (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
88% over limit
Discharged 56.3 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Mercury, total [as Hg]
0% over limit
Discharged 0.0000113 mg/L against a permitted limit of 0.00005 mg/L (DAILY MX)
DMR, Limited - Overdue
Copper, total [as Cu]
0% over limit
Discharged 0.0369 mg/L against a permitted limit of 0.074 mg/L (DAILY MX)
DMR, Limited - Overdue
Phosphorus, total [as P]
0% over limit
Discharged 8.80759993 kg/d against a permitted limit of 0 kg/d (DAILY MX)
DMR, Monitor Only - Overdue
Phosphorus, total [as P]
0% over limit
Discharged 1.5 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
Mercury, total [as Hg]
0% over limit
Discharged 0.00032 kg/d against a permitted limit of 0 kg/d (DAILY MX)
DMR, Monitor Only - Overdue
Solids, total suspended
58% over limit
Discharged 71 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Lead, total [as Pb]
0% over limit
Discharged 0.0015 mg/L against a permitted limit of 0.02 mg/L (DAILY MX)
DMR, Limited - Overdue
Solids, suspended percent removal
30% over limit
Discharged 80.5 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
60% over limit
Discharged 289.92439756 kg/d against a permitted limit of 181.59999847 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
76% over limit
Discharged 359.74959698 kg/d against a permitted limit of 204.29999828 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
Carbonaceous oxygen demand, % removal
54% over limit
Discharged 76.9 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
136% over limit
Discharged 58.9 mg/L against a permitted limit of 25 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
115% over limit
Discharged 243.93419795 kg/d against a permitted limit of 113.49999905 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
92% over limit
Discharged 76.6 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Lead, total [as Pb]
0% over limit
Discharged 0.00908 kg/d against a permitted limit of 0.0908 kg/d (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
71% over limit
Discharged 233.26519804 kg/d against a permitted limit of 136.19999886 kg/d (MO AVG)
DMR, Limited - Numeric Violation
January 31, 2025
Solids, total suspended
11% over limit
Discharged 226.0465981 kg/d against a permitted limit of 204.29999828 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
30% over limit
Discharged 176.87839851 kg/d against a permitted limit of 136.19999886 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
4% over limit
Discharged 118.40319901 kg/d against a permitted limit of 113.49999905 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
80% over limit
Discharged 81 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
80% over limit
Discharged 54 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
44% over limit
Discharged 36.1 mg/L against a permitted limit of 25 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
15% over limit
Discharged 46 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
December 31, 2024
Solids, total suspended
3% over limit
Discharged 209.52099824 kg/d against a permitted limit of 204.29999828 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
21% over limit
Discharged 81.9 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
Carbonaceous oxygen demand, % removal
19% over limit
Discharged 82.2 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
October 31, 2024
Nitrogen, ammonia total [as N]
555% over limit
Discharged 71.3233994 kg/d against a permitted limit of 10.89599991 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Coliform, fecal general
15% over limit
Discharged 460 MPN/100mL against a permitted limit of 400 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
Oxygen demand, ultimate
40% over limit
Discharged 111.6 mg/L against a permitted limit of 80 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
942% over limit
Discharged 25 mg/L against a permitted limit of 2.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2024
Oxygen demand, ultimate
36% over limit
Discharged 108.4 mg/L against a permitted limit of 80 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
567% over limit
Discharged 16 mg/L against a permitted limit of 2.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
899% over limit
Discharged 108.82379909 kg/d against a permitted limit of 10.89599991 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2024
Nitrogen, ammonia total [as N]
504% over limit
Discharged 65.82999945 kg/d against a permitted limit of 10.89599991 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Flow, in conduit or thru treatment plant
17% over limit
Discharged 1.4 MGD against a permitted limit of 1.2 MGD (MO AVG)
DMR, Limited - Numeric Violation
Oxygen demand, ultimate
1% over limit
Discharged 366.15099692 kg/d against a permitted limit of 363.19999695 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
52% over limit
Discharged 310.35439739 kg/d against a permitted limit of 204.29999828 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
Oxygen demand, ultimate
0% over limit
Discharged 80.3 mg/L against a permitted limit of 80 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
47% over limit
Discharged 66 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
10% over limit
Discharged 149.77459874 kg/d against a permitted limit of 136.19999886 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
483% over limit
Discharged 14 mg/L against a permitted limit of 2.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
July 31, 2024
Nitrogen, ammonia total [as N]
588% over limit
Discharged 74.90999937 kg/d against a permitted limit of 10.89599991 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
650% over limit
Discharged 18 mg/L against a permitted limit of 2.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen demand, ultimate
6% over limit
Discharged 85 mg/L against a permitted limit of 80 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen demand, ultimate
10% over limit
Discharged 399.51999664 kg/d against a permitted limit of 363.19999695 kg/d (MO AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (24 days ago)