Newswise — A 2019 Airline Water Study released today by DietDetective.com and the Hunter College NYC Food Policy Center reveals that the quality of drinking water varies by airline, and many airlines have possibly provided passengers with unhealthy water.

Unhealthy water violates the federal government’s Aircraft Drinking Water Rule (ADWR), which was implemented in 2011 and requires airlines to provide passengers and flight crew with safe drinking water. 

The 2019 Airline Water Study ranks 11 major and 12 regional airlines mainly by the quality of water they provided onboard its flights. Each airline was given a “Water Health Score” (5 = highest rating, 0 = lowest) based on 10 criteria, including fleet size, ADWR violations, positive E. coli and coliform water sample reports and cooperation in providing answers to water-quality questions. A score of 3.0 or better indicates that the airline has relatively safe, clean water.

"Alaska Airlines and Allegiant win the top spot with the safest water in the sky, and Hawaiian Airlines finishes No. 2," says Charles Platkin, PhD, JD, MPH, the editor of DietDetective.com and the executive director of the Hunter College NYC Food Policy Center.

The airlines with the worst scores are JetBlue and Spirit Airlines, the study shows. “Except for Piedmont Airlines, regional airlines need to improve their onboard water safety,” Platkin says.

The ADWR requires airlines to take samples from their water tanks to test for coliform bacteria and possible E. coli. Airlines are also required to disinfect and flush each aircraft’s water tank four times per year. Alternatively, an airline may choose to disinfect and flush once a year, but then it must test monthly. (See: Electronic Code of Federal Regulations)

 The 2019 Airline Water Study also finds that the Environmental Protection Agency – one of the federal agencies responsible for ensuring safe aircraft drinking water– rarely levies civil penalties to airlines in violation of the ADWR. 

Here are the study’s findings:

  • The major airlines receiving the highest Airline Water Health Score are Allegiant and Alaska – each with a score of 3.3 on a 0-to-5 scale. Hawaiian Airlines is a close second at 3.1.  
  • Piedmont Airlines, which operates American Eagle flights, is the highest-rated regional carrier with a score of 4.33.
  • Among major airlines, Spirit and JetBlue tied for the lowest score of 1 on a 0-to-5 scale.   
  • Nearly all regional airlines, except Piedmont, have poor Water Health Scores and a large number of ADWR violations. Republic Airways (which flies for United Express, Delta Connection and American Eagle) has the lowest score at 0.44 on a 0-to-5 scale and ExpressJet is second-lowest at 0.56. ExpressJet averages 3.36 ADWR violations per aircraft.
  • The number of ADWR violations by all airlines in 2018 was significantly less than the number in 2012, the first year after the ADWR was enacted. For major airlines, violations have decreased 69% (262 to 81), while violations among regional airlines have decreased 71% (351 to 103). However, the decrease might reflect a lack of enforcement by the EPA, which has issued few penalties in recent years. 
  • The “Shame on You” Award goes to the EPA and nearly all major airlines (regional airlines weren’t contacted) for their very poor response time and lack of cooperation answering detailed questions. The EPA didn’t answer most penalty-related questions, and Spirit, Allegiant and Frontier did not respond to any questions. Very weak responses – and responses that didn’t address questions – were provided by American, United, and JetBlue, which had a large number of violations during the past seven years.
  • Testing for coliform bacteria is important, because their presence in drinking water indicates that disease-causing organisms (pathogens) could be in the water system.
  • When an aircraft's water sample tests positive for coliform, it must be tested again to determine if E. coli is present. If E. coli is not present, the airline must take repeat samples within 24 hrs, disinfect and flush the water system within 72 hrs. Or the airline can shut down the water system within 72 hrs and then disinfect and flush. If the sample is E. Coli positive, the airline must shut off public access to the water system within 24 hrs and disinfect and flush. 
  • The ADWR does not require the same testing as the National Primary Drinking Water Regulations, which includes other microorganisms in addition to total coliform. (See here). 
  • An aircraft flies to numerous destinations and may pump drinking water into its tanks from various sources at domestic and international locations. The water quality onboard also depends on the safety of the equipment used to transfer the water, such as water cabinets, trucks, carts and hoses.
  • Here’s the bottom-line advice from DietDetective.com and the Hunter College NYC Food Policy Center. To be extra safe:  
    • NEVER drink any water onboard that isn’t in a sealed bottle, 
    • Do not drink coffee or tea onboard, 
    • Do not wash your hands in the bathroom; bring hand-sanitizer with you instead.  

Airline Water Health Scores At-a-Glance (5 = highest rating, 0 = lowest):

Major Airlines

Alaska Airlines: 3.3, Allegiant Air: 3.3, Hawaiian Airlines: 3.1, Frontier Airlines: 2.6, Southwest Airlines: 2.4, Delta Air Lines: 1.6, American Airlines: 1.5, United Airlines: 1.2, JetBlue: 1, Spirit Airlines: 1 

Regional Airlines

Piedmont Airlines: 4.33, Sun Country Airlines: 2.78, Envoy Air: 2.11, GoJet Airlines: 2, Trans States Airlines: 1.78, Compass Airlines 1.22, PSA Airlines: 1.22, SkyWest Airlines 1.11, Endeavor Air: 0.78, Air Wisconsin Airlines: 0.68, ExpressJet Airlines: 0.56, Republic Airways: 0.44  

Airline Water Study Results*

Major Airlines

Alaska Airlines

Onboard Water Health Score: 3.3 / 5 Stars

Aircraft Fleet Size: 335

Total ADWR Violations (2012-2019): 2

Avg # of ADWR Violations per Aircraft: 0.01

Total Water Samples Testing Positive For E. Coli (2012-2019): 1

Total Water Samples Testing Positive For Coliform (2012-2019): 64

Cooperation In Water Investigation: Not helpful 

Comments: While Alaska Airlines has a very low number of violations per aircraft, and received the highest water score. The airline has several unrecorded violations for its failure to collect repeat or follow-up samples of a coliform-positive result. 

Allegiant

Onboard Water Health Score: 3.3 / 5 Stars

Aircraft Fleet Size: 91

Total ADWR Violations (2012-2019): 6

Avg # of ADWR Violations per Aircraft: 0.06

Total Water Samples Testing Positive For E. Coli (2012-2019): 2

Total Water Samples Testing Positive For Coliform (2012-2019): 0

Cooperation In Water Investigation: Not helpful

Comments: Allegiant has a very low number of average violations per aircraft and received the highest water score.

Hawaiian Airlines

Onboard Water Health Score: 3.1 / 5 Stars

Aircraft Fleet Size: 57

Total ADWR Violations (2012-2019): 25

Avg # of ADWR Violations per Aircraft: 0.44

Total Water Samples Testing Positive For E. Coli (2012-2019): 0

Total Water Samples Testing Positive For Coliform (2012-2019): 7

Cooperation In Water Investigation: Somewhat helpful

Comments: The airline says it samples water twice as often as EPA guidelines recommend. However, the airline had a relatively high average number of violations per aircraft. It is also important to note that 15 of the airline’s 25 violations (since 2012) were in the last 18 months.

Frontier Airlines

Onboard Water Health Score: 2.6 / 5 Stars

Aircraft Fleet Size: 91

Total ADWR Violations (2012-2019): 19 

Avg # of ADWR Violations per Aircraft: 0.21

Total Water Samples Testing Positive For E. Coli (2012-2019): 4

Total Water Samples Testing Positive For Coliform (2012-2019): 8

Cooperation In Water Investigation: Not helpful

Comments: Frontier had a relatively high number of violations for failure to conduct routine monitoring.

Southwest Airlines Co. 

Onboard Water Health Score: 2.4 / 5 Stars

Aircraft Fleet Size: 754

Total ADWR Violations (2012-2019): 33

Avg # of ADWR Violations per Aircraft: 0.04

Total Water Samples Testing Positive For E. Coli (2012-2019): 2

Total Water Samples Testing Positive For Coliform (2012-2019): 122 

Cooperation In Water Investigation: Not helpful 

Comments: Southwest had a very low number of violations per aircraft. However, the airline had an elevated number of violations for failure to conduct routine monitoring and failure to perform corrective actions as required. 

Delta Air Lines

Onboard Water Health Score: 1.6 / 5 Stars

Aircraft Fleet Size: 916

Total ADWR Violations (2012-2019): 213 

Avg # of ADWR Violations per Aircraft: 0.23

Total Water Samples Testing Positive For E. Coli (2012-2019): 15

Total Water Samples Testing Positive For Coliform (2012-2019): 359 

Cooperation In Water Investigation: Helpful 

Comments: Delta is the only airline to actually written a blog post on its water. However, the airline had a relatively high number of average violations per aircraft and a very high number of positive E. Coli lavatory samples. Additionally, the airline had a very high number of violations for failure to conduct routine monitoring and a high number of violations for failure to perform corrective actions. Endeavor Air, a subsidiary of Delta, also did not do very well with a score of 0.78.

American Airlines

Onboard Water Health Score: 1.5 / 5 Stars

Aircraft Fleet Size: 968

Total ADWR Violations (2012-2019): 108 

Avg # of ADWR Violations per Aircraft: 0.11

Total Water Samples Testing Positive For E. Coli (2012-2019): 23

Total Water Samples Testing Positive For Coliform (2012-2019): 660 

Cooperation In Water Investigation: Not helpful

Comments: American Airlines had a very high number of galley water samples testing positive for E.Coli. Additionally, American had a relatively high number of violations for failure to conduct routine monitoring and failure to perform corrective actions and repeat or follow up samples. American also owns regional carriers, PSA Airlines and Envoy Air, which have very poor onboard water records. However, its other subsidiary, Piedmont Airlines, received the highest water score. 

 

United Airlines

Onboard Water Health Score: 1.2 / 5 Stars

Aircraft Fleet Size: 786

Total ADWR Violations (2012-2019): 79

Avg # of ADWR Violations per Aircraft: 0.10

Total Water Samples Testing Positive For E. Coli (2012-2019): 3

Total Water Samples Testing Positive For Coliform (2012-2019): 205

Cooperation In Water Investigation: Not helpful

Comments: The airline had a high number of violations for failure to conduct routine monitoring and failure to collect repeat or follow-up samples of a coliform-positive result. Additionally, United is associated with the regionals Air Wisconsin, ExpressJet and Trans States Airlines, which have very poor onboard water records. 

JetBlue

Onboard Water Health Score: 1 / 5 Stars

Aircraft Fleet Size: 254

Total ADWR Violations (2012-2019): 354 

Avg # of ADWR Violations per Aircraft: 1.40

Total Water Samples Testing Positive For E. Coli (2012-2019): 9

Total Water Samples Testing Positive For Coliform (2012-2019): 144

Cooperation In Water Investigation: Not Helpful

Comments: A poor response from JetBlue representatives and a poor water safety record. JetBlue had the highest number of total ADWR violations among the major airlines and a very high number of average number of violations per aircraft. The airline also had a relatively high number of water samples testing positive for E. coli and a high number of violations for failure to conduct routine monitoring, failure to perform required corrective actions and failure to collect repeat or follow-up samples of a coliform-positive result.

Spirit Airlines

Onboard Water Health Score: 1 / 5  Stars

Aircraft Fleet Size: 135

Total ADWR Violations (2012-2019): 193

Avg # of ADWR Violations per Aircraft: 1.43

Total Water Samples Testing Positive For E. Coli (2012-2019): 1

Total Water Samples Testing Positive For Coliform (2012-2019): 31

Cooperation In Water Investigation: Not helpful

Comments: Spirit had the highest number of average of violations per aircraft among the major airlines. Additionally, the airline had a high number of violations for failure to conduct routine monitoring and failure to perform corrective actions as required.

Regional Airlines 

Piedmont Airlines (operates as American Eagle, owned by American Airlines)

Onboard Water Health Score: 4.33 / 5 Stars

Aircraft Fleet Size: 60

Total ADWR Violations (2012-2019): 1

Avg # of ADWR Violations per Aircraft: 0.02

Total Water Samples Testing Positive For E. Coli (2012-2019): 0

Total Water Samples Testing Positive For Coliform (2012-2019): 5

Comments: Piedmont, a subsidiary of American Airlines Group, had the least number of ADWR violations among all regional carriers.

Sun Country Airlines 

Onboard Water Health Score: 2.78 / 5 Stars

Aircraft Fleet Size: 30

Total ADWR Violations (2012-2019): 19

Avg # of ADWR Violations per Aircraft: 0.63

Total Water Samples Testing Positive For E. Coli (2012-2019): 2

Total Water Samples Testing Positive For Coliform (2012-2019): 8

Comments: Sun Country had a relatively high number of average violations per aircraft. 

Envoy Air (operates as American Eagle, owned by American Airlines)

Onboard Water Health Score: 2.11 / 5 Stars

Aircraft Fleet Size: 63

Total ADWR Violations (2012-2019): 63

Avg # of ADWR Violations per Aircraft: 1.00

Total Water Samples Testing Positive For E. Coli (2012-2019): 24

Total Water Samples Testing Positive For Coliform (2012-2019): 172 

Comments: Envoy had a very high number lavatory water samples testing positive for E. Coli. Additionally, the airline has a relatively high number of violations for failure to perform corrective actions and a high number of violations for failure to collect repeat or follow-up samples of a coliform-positive result. 

GoJet Airlines (operates as United Express, Delta Connection)

Onboard Water Health Score: 2 / 5 Stars

Aircraft Fleet Size: 53

Total ADWR Violations (2012-2019): 26

Avg # of ADWR Violations per Aircraft: 0.49

Total Water Samples Testing Positive For E. Coli (2012-2019): 2

Total Water Samples Testing Positive For Coliform (2012-2019): 64

Comments: GoJet Airlines had a relatively high number of average violations per aircraft. As of August 6, 2019, Delta Connection ended its partnership with Gojet and Compass Airlines. 

Trans States Airlines (operates as United Express)

Onboard Water Health Score: 1.78 / 5 Stars

Aircraft Fleet Size: 46

Total ADWR Violations (2012-2019): 33

Avg # of ADWR Violations per Aircraft: 0.72

Total Water Samples Testing Positive For E. Coli (2012-2019): 2

Total Water Samples Testing Positive For Coliform (2012-2019): 0

Comments: Trans States Airlines had a relatively high number of violations per aircraft.

Compass Airlines (operates as Delta Connection and American Eagle)

Onboard Water Health Score: 1.22 / 5 Stars

Aircraft Fleet Size: 56

Total ADWR Violations (2012-2019): 113

Avg # of ADWR Violations per Aircraft: 2.02

Total Water Samples Testing Positive For E. Coli (2012-2019): 0

Total Water Samples Testing Positive For Coliform (2012-2019): 65

Comments: Compass had a very high number of violations per aircraft and a very high number of violations for failure to conduct routine monitoring, failure to perform corrective actions as required and failure to collect repeat or follow-up samples of a coliform-positive result. 

Mesa Airlines (operates as United Express and American Eagle)

Onboard Water Health Score: 1.22 / 5 Stars

Aircraft Fleet Size: 145

Total ADWR Violations (2012-2019): 73

Avg # of ADWR Violations per Aircraft: 0.50

Total Water Samples Testing Positive For E. Coli (2012-2019): 7

Total Water Samples Testing Positive For Coliform (2012-2019): 67

Comments: Mesa had a relatively high number of violations per aircraft.

PSA Airlines (operates as American Eagle and owned by American Airlines)

Onboard Water Health Score: 1.22 / 5 Stars

Aircraft Fleet Size: 144

Total ADWR Violations (2012-2019): 78

Avg # of ADWR Violations per Aircraft: 0.54

Total Water Samples Testing Positive For E. Coli (2012-2019): 7

Total Water Samples Testing Positive For Coliform (2012-2019): 89

Comments: PSA had a relatively high number of violations for lavatory water samples testing positive for E. Coli and failure to collect repeat or follow-up samples of a coliform-positive result. 

SkyWest Airlines (operates as United Express, Delta Connection, American Eagle, Alaska SkyWest)   

Onboard Water Health Score: 1.11 / 5 Stars

Aircraft Fleet Size: 512

Total ADWR Violations (2012-2019): 117

Avg # of ADWR Violations per Aircraft: 0.23

Total Water Samples Testing Positive For E. Coli (2012-2019): 25 

Total Water Samples Testing Positive For Coliform (2012-2019): 1042

Comments: SkyWest had a very high number of the lavatory water samples testing positive for E.Coli. Additionally, the airline had a very high number of violations for failure to conduct routine monitoring and a very high number of violations for failure to collect repeat or follow-up samples of a coliform-positive result. 

Endeavor Air (operates as Delta Connection owned Delta Air Lines.)

Onboard Water Health Score: 0.78 / 5 Stars

Aircraft Fleet Size: 157

Total ADWR Violations (2012-2019): 322 

Avg # of ADWR Violations per Aircraft: 2.05

Total Water Samples Testing Positive For E. Coli (2012-2019): 14

Total Water Samples Testing Positive For Coliform (2012-2019): 430

Comments: Endeavor had a relatively high number of lavatory water samples testing positive for E. Coli and a very high number of average violations per aircraft. Additionally, the airline had a very high number of violations for failure to conduct routine monitoring, failure to perform corrective actions as required and failure to collect repeat or follow-up samples of a coliform-positive result. 

Air Wisconsin Airlines (operates as United Express)

Onboard Water Health Score: 0.67 / 5 Stars

Aircraft Fleet Size: 64

Total ADWR Violations (2012-2019): 188

Avg # of ADWR Violations per Aircraft: 2.94

Total Water Samples Testing Positive For E. Coli (2012-2019): 4

Total Water Samples Testing Positive For Coliform (2012-2019): 133

Comments: Air Wisconsin had a very high number of average violations per aircraft and violations for failure to conduct routine monitoring and failure to collect repeat or follow-up samples of a coliform-positive result. The airline also had a relatively high number of violations for failure to perform required corrective actions. 

ExpressJet Airlines Inc (operates as United Express)

Onboard Water Health Score: 0.56 / 5 Stars

Aircraft Fleet Size: 128

Total ADWR Violations (2012-2019): 430

Avg # of ADWR Violations per Aircraft: 3.36

Total Water Samples Testing Positive For E. Coli (2012-2019): 12

Total Water Samples Testing Positive For Coliform (2012-2019): 679

Comments: Abysmal. ExpressJet had the highest average number of violations. The airline also had a very high number of lavatory water samples testing positive for E. coli and violations for failure to conduct routine monitoring, failure to perform required corrective actions and failure to collect repeat or follow-up samples of a coliform-positive result.

Republic Airways (operates as United Express, Delta Connection, American Eagle)

Onboard Water Health Score: 0.44 / 5 Stars 

Aircraft Fleet Size: 191

Total ADWR Violations (2012-2019): 132

Avg # of ADWR Violations per Aircraft: 0.69

Total Water Samples Testing Positive For E. Coli (2012-2019): 6

Total Water Samples Testing Positive For Coliform (2012-2019): 125

Comments: Republic had a relatively high number of average violations per aircraft and a very high number of violations for failure to conduct routine monitoring and failure to perform required corrective actions. The airline also had a high number of violations for failure to collect repeat or follow-up samples of a coliform-positive result.

*In compiling these numbers, we categorized airlines as either Major Airline or Regional. Charter and cargo airlines were excluded. Our study is not all-encompassing and includes only those airlines that have violations registered in the EPA’s ADWR Public Compliance Reports. As a result, some regional airlines may have been excluded even if they currently have an active presence in national aviation. Furthermore, the EPA’s Compliance Reports site does not provide any analytics for the data; the aircraft sampling data was especially difficult to sort through. There were also several instances where the data from one page did not match the values provided by another. The EPA should consider cleaning up their data to resolve inconsistencies and make the site more researcher-friendly. 

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