CITY OF HILLSBORO WWTP
NPDES ID: TX0023108
S — SNC: Compliance schedule violation
The facility missed a deadline in its compliance schedule by more than 90 days.
Violations
March 31, 2026
Solids, total suspended
15% over limit
Discharged 23 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
February 28, 2026
Copper, total [as Cu]
171% over limit
Discharged 0.187 mg/L against a permitted limit of 0.069 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
20% over limit
Discharged 6 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
61% over limit
Discharged 0.0514 mg/L against a permitted limit of 0.032 mg/L (DAILY AV)
DMR, Limited - Numeric Violation
January 31, 2026
Solids, total suspended
8% over limit
Discharged 36.86933969 kg/d against a permitted limit of 34.05 kg/d (DAILY AV)
DMR, Limited - Numeric Violation
Solids, total suspended
60% over limit
Discharged 32 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
93% over limit
Discharged 9.63 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Numeric Violation
October 31, 2025
Nitrogen, ammonia total [as N]
67% over limit
Discharged 2.17 mg/L against a permitted limit of 1.3 mg/L (DAILY AV)
DMR, Limited - Numeric Violation
August 31, 2025
Solids, total suspended
5% over limit
Discharged 5.25 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
5% over limit
Discharged 1.36 mg/L against a permitted limit of 1.3 mg/L (DAILY AV)
DMR, Limited - Numeric Violation
July 31, 2025
Flow, in conduit or thru treatment plant
18% over limit
Discharged 6.22512009 MGD against a permitted limit of 5.29344 MGD (2HR PEAK)
DMR, Limited - Numeric Violation
June 30, 2025
Flow, in conduit or thru treatment plant
18% over limit
Discharged 6.24384009 MGD against a permitted limit of 5.29344 MGD (2HR PEAK)
DMR, Limited - Numeric Violation
May 31, 2025
Flow, in conduit or thru treatment plant
18% over limit
Discharged 6.22512009 MGD against a permitted limit of 5.29344 MGD (2HR PEAK)
DMR, Limited - Numeric Violation
April 30, 2025
Solids, total suspended
100% over limit
Discharged 40 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
33% over limit
Discharged 12.0945599 kg/d against a permitted limit of 9.07999992 kg/d (DAILY AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
158% over limit
Discharged 3.35 mg/L against a permitted limit of 1.3 mg/L (DAILY AV)
DMR, Limited - Numeric Violation
Solids, total suspended
60% over limit
Discharged 8 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
48% over limit
Discharged 14.8 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
November 30, 2024
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 2.5 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Overdue
E. coli
0% over limit
Discharged 1 MPN/100mL against a permitted limit of 399 MPN/100mL (DAILY MX)
DMR, Limited - Overdue
Copper, total [as Cu]
0% over limit
Discharged 0.0193858 kg/d against a permitted limit of 0.21792 kg/d (DAILY AV)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 15.36699187 kg/d against a permitted limit of 34.05 kg/d (DAILY AV)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 4.125 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.43 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 13 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 3.98304006 MGD against a permitted limit of 5.29344 MGD (2HR PEAK)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.98 MGD against a permitted limit of 0 MGD (DAILY AV)
DMR, Monitor Only - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 6 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 1.1 MGD against a permitted limit of 1.81 MGD (ANNL AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 1.28527399 kg/d against a permitted limit of 9.07999992 kg/d (DAILY AV)
DMR, Limited - Overdue
pH
0% over limit
Discharged 6.8 SU against a permitted limit of 6 SU (MINIMUM)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 1.2 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 6.2 mg/L against a permitted limit of 6 mg/L (MO MIN)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.345 mg/L against a permitted limit of 1.3 mg/L (DAILY AV)
DMR, Limited - Overdue
pH
0% over limit
Discharged 6.9 SU against a permitted limit of 9 SU (MAXIMUM)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 9.31335592 kg/d against a permitted limit of 34.05 kg/d (DAILY AV)
DMR, Limited - Overdue
October 31, 2024
Flow, in conduit or thru treatment plant
0% over limit
Discharged 1.2 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 6.62 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 3.8 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 6.1 mg/L against a permitted limit of 6 mg/L (MO MIN)
DMR, Limited - Overdue
pH
0% over limit
Discharged 6.9 SU against a permitted limit of 9 SU (MAXIMUM)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 1.1 MGD against a permitted limit of 1.81 MGD (ANNL AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 6 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 5.79213195 kg/d against a permitted limit of 9.07999992 kg/d (DAILY AV)
DMR, Limited - Overdue
Copper, total [as Cu]
0% over limit
Discharged 0.0193858 kg/d against a permitted limit of 0.21792 kg/d (DAILY AV)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 13.16418389 kg/d against a permitted limit of 34.05 kg/d (DAILY AV)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
8% over limit
Discharged 1.4 mg/L against a permitted limit of 1.3 mg/L (DAILY AV)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
8% over limit
Discharged 1.4 mg/L against a permitted limit of 1.3 mg/L (DAILY AV)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 6.8 SU against a permitted limit of 6 SU (MINIMUM)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 14.71323188 kg/d against a permitted limit of 34.05 kg/d (DAILY AV)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 3.4 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 9 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 1.02 MGD against a permitted limit of 0 MGD (DAILY AV)
DMR, Monitor Only - Overdue
September 30, 2024
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.53 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 1 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
pH
0% over limit
Discharged 6.8 SU against a permitted limit of 9 SU (MAXIMUM)
DMR, Limited - Overdue
pH
0% over limit
Discharged 6.8 SU against a permitted limit of 6 SU (MINIMUM)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.93 MGD against a permitted limit of 0 MGD (DAILY AV)
DMR, Monitor Only - Overdue
Whole Effluent Toxicity [WET] - C. dubia
100% over limit
Discharged 0 % against a permitted limit of 100 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 7.91730593 kg/d against a permitted limit of 34.05 kg/d (DAILY AV)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 3 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Overdue
Copper, total [as Cu]
0% over limit
Discharged 0.0039 mg/L against a permitted limit of 0.069 mg/L (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 7.91730593 kg/d against a permitted limit of 34.05 kg/d (DAILY AV)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 6.2 mg/L against a permitted limit of 6 mg/L (MO MIN)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 3 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Overdue
Whole Effluent Toxicity [WET] - C. dubia
100% over limit
Discharged 0 % against a permitted limit of 100 % (7 DA MIN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.425 mg/L against a permitted limit of 1.3 mg/L (DAILY AV)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 2.25 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 2.25 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 1.1 MGD against a permitted limit of 1.81 MGD (ANNL AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 1.49547599 kg/d against a permitted limit of 9.07999992 kg/d (DAILY AV)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 3.98448006 MGD against a permitted limit of 5.29344 MGD (2HR PEAK)
DMR, Limited - Overdue
August 31, 2024
Flow, in conduit or thru treatment plant
0% over limit
Discharged 1.1 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
pH
0% over limit
Discharged 6.8 SU against a permitted limit of 9 SU (MAXIMUM)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 11.28598591 kg/d against a permitted limit of 34.05 kg/d (DAILY AV)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 2 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 3.11 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Overdue
Copper, total [as Cu]
0% over limit
Discharged 0.0039 mg/L against a permitted limit of 0.069 mg/L (DAILY MX)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 2.80117998 kg/d against a permitted limit of 9.07999992 kg/d (DAILY AV)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 12 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 7.25537394 kg/d against a permitted limit of 34.05 kg/d (DAILY AV)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 4.44 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.772 mg/L against a permitted limit of 1.3 mg/L (DAILY AV)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 6.1 mg/L against a permitted limit of 6 mg/L (MO MIN)
DMR, Limited - Overdue
pH
0% over limit
Discharged 6.8 SU against a permitted limit of 6 SU (MINIMUM)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.99 MGD against a permitted limit of 1.81 MGD (ANNL AVG)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 3.98304006 MGD against a permitted limit of 5.29344 MGD (2HR PEAK)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.96 MGD against a permitted limit of 0 MGD (DAILY AV)
DMR, Monitor Only - Overdue
July 31, 2024
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 3.88 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 14.96202387 kg/d against a permitted limit of 34.05 kg/d (DAILY AV)
DMR, Limited - Overdue
Solids, total suspended
49% over limit
Discharged 7.44 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Overdue
Solids, total suspended
49% over limit
Discharged 7.44 mg/L against a permitted limit of 5 mg/L (DAILY AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
76% over limit
Discharged 17.6 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
76% over limit
Discharged 17.6 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
70% over limit
Discharged 34 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
70% over limit
Discharged 34 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
74% over limit
Discharged 2.256 mg/L against a permitted limit of 1.3 mg/L (DAILY AV)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
74% over limit
Discharged 2.256 mg/L against a permitted limit of 1.3 mg/L (DAILY AV)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 6.9 SU against a permitted limit of 9 SU (MAXIMUM)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 1.01 MGD against a permitted limit of 1.81 MGD (ANNL AVG)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 3.98304006 MGD against a permitted limit of 5.29344 MGD (2HR PEAK)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 8.67820993 kg/d against a permitted limit of 9.07999992 kg/d (DAILY AV)
DMR, Limited - Overdue
Copper, total [as Cu]
0% over limit
Discharged 0.0193858 kg/d against a permitted limit of 0.21792 kg/d (DAILY AV)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 1.3 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 62 mg/L against a permitted limit of 6 mg/L (MO MIN)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 28.64195176 kg/d against a permitted limit of 34.05 kg/d (DAILY AV)
DMR, Limited - Overdue
pH
0% over limit
Discharged 6.7 SU against a permitted limit of 6 SU (MINIMUM)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 1.02 MGD against a permitted limit of 0 MGD (DAILY AV)
DMR, Monitor Only - Overdue
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (22 days ago)