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States → Delaware

WILMINGTON WATER DEPARTMENT

PWS ID: DE0000663 · WILMINGTON, Delaware 19801

PFAS Detected

6 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
107,976
Total Violations
30
Health-Based Violations
13
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
37,915
County
New Castle
School/Daycare
No
MCL Violations
4
Monitoring Violations
13
Treatment Tech Violations
9

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Surface Water Treatment Rule TT 7 2004
Cryptosporidium MR 4 2015
Coliform (TCR) MCL 4 2013
Long Term 2 Enhanced Surface Water Treatment Rule MR 4 2015
Consumer Confidence Rule Other 3 2015
Revised Total Coliform Rule MON 3 2023
Coliform (TCR) MR 2 2001
Long Term 2 Enhanced Surface Water Treatment Rule TT 2 2017

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 40 of 240 samples detected PFAS.

Contaminant Date Result MRL Status
NMeFOSAA 8/9/2023 <0.006 µg/L 0.006 µg/L Not Detected
lithium 8/9/2023 <9 µg/L 9 µg/L Not Detected
PFUnA 8/9/2023 <0.002 µg/L 0.002 µg/L Not Detected
PFHxA 8/9/2023 0.0077 µg/L 0.003 µg/L Detected
PFDoA 8/9/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFDA 8/9/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFOA 8/9/2023 0.0068 µg/L 0.004 µg/L Detected
11Cl-PF3OUdS 8/9/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFOS 8/9/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFBS 8/9/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFTA 8/9/2023 <0.008 µg/L 0.008 µg/L Not Detected
PFHxS 8/9/2023 <0.003 µg/L 0.003 µg/L Not Detected
9Cl-PF3ONS 8/9/2023 <0.002 µg/L 0.002 µg/L Not Detected
NEtFOSAA 8/9/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFTrDA 8/9/2023 <0.007 µg/L 0.007 µg/L Not Detected
6:2 FTS 8/9/2023 <0.005 µg/L 0.005 µg/L Not Detected
ADONA 8/9/2023 <0.003 µg/L 0.003 µg/L Not Detected
HFPO-DA 8/9/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFNA 8/9/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFBA 8/9/2023 0.0102 µg/L 0.005 µg/L Detected
PFHpA 8/9/2023 0.0037 µg/L 0.003 µg/L Detected
4:2 FTS 8/9/2023 <0.003 µg/L 0.003 µg/L Not Detected
8:2 FTS 8/9/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFMPA 8/9/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFMBA 8/9/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFEESA 8/9/2023 <0.003 µg/L 0.003 µg/L Not Detected
NFDHA 8/9/2023 <0.02 µg/L 0.02 µg/L Not Detected
PFPeS 8/9/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFHpS 8/9/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 8/9/2023 0.0082 µg/L 0.003 µg/L Detected
PFDA 8/9/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFOA 8/9/2023 0.0067 µg/L 0.004 µg/L Detected
PFOS 8/9/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFNA 8/9/2023 <0.004 µg/L 0.004 µg/L Not Detected
PFHxS 8/9/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 8/9/2023 0.0040 µg/L 0.003 µg/L Detected
PFBS 8/9/2023 0.0033 µg/L 0.003 µg/L Detected
NMeFOSAA 8/9/2023 <0.006 µg/L 0.006 µg/L Not Detected
NEtFOSAA 8/9/2023 <0.005 µg/L 0.005 µg/L Not Detected
PFDoA 8/9/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFTA 8/9/2023 <0.008 µg/L 0.008 µg/L Not Detected
6:2 FTS 8/9/2023 <0.005 µg/L 0.005 µg/L Not Detected
lithium 8/9/2023 <9 µg/L 9 µg/L Not Detected
PFTrDA 8/9/2023 <0.007 µg/L 0.007 µg/L Not Detected
PFHxA 8/9/2023 0.0077 µg/L 0.003 µg/L Detected
PFUnA 8/9/2023 <0.002 µg/L 0.002 µg/L Not Detected
11Cl-PF3OUdS 8/9/2023 <0.005 µg/L 0.005 µg/L Not Detected
9Cl-PF3ONS 8/9/2023 <0.002 µg/L 0.002 µg/L Not Detected
ADONA 8/9/2023 <0.003 µg/L 0.003 µg/L Not Detected
PFBA 8/9/2023 0.0105 µg/L 0.005 µg/L Detected
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.