The certification of drinking water for a Public Water Supply (PWS) is regulated by the Safe Drinking Water Act (SDWA) under EPA, and the State of Louisiana, under its primacy status, administers this certification though the Department of Health and Hospitals, Office of Public Health, Drinking Water. Under the state's sanitary code only LADHH can certify a PWS for drinking water.

After Katrina the burden imposed on the Sewerage and Water Board by EPA/DHH was to prove the stability of the entire system. By September 12th, water was being produced which could meet regulatory requirements, but it took almost a month to show, among other items of concern, that there existed the ability to pump water from the river, bring into the plant treatment chemicals, treat it properly, pump the water from the plant and distribute it with adequate pressure throughout the city. Also, over six hundred investigative bacteriological samples were taken, even before the Board requested the State to consider a formal testing period mandated by them. On October 6th the water was certified for drinking west of the Industrial Canal, and on December 8th New Orleans East and a portion of the lower ninth ward was certified on May 8, 2006. Please be aware that certain groups have expressed concern that the certification of drinking water proceeded too quickly, and that further controls needed to be placed in effect before drinking status was achieved.

The utter devastation of the northern part of the lower ninth ward has made it impossible to establish positive control over the water distribution system. With so many leaks and openings to the water mains, it is not possible to maintain water pressure consistently. This could lead to back-siphonage, drawing contaminated water into the water pipes. This would have the effect of possibly providing a danger to public health. Until debris is cleared and the water infrastructure is reestablished it will be impossible to guarantee LADHH that positive control has been achieved. The water purification plant does have physical limits to the amount of water that can be produced and pumped. Excessive water production needed by the devastated area only places the city at large in jeopardy.