MINOT (AP) - The U.S. Bureau of Reclamation is providing more time for comment on a draft environmental study for the Northwest Area Water Supply project.

The comment period has been extended to March 26. The initial period expired in late February, but officials in the Canadian province of Manitoba asked for more time.

The study is looking into treatment options for Missouri River water that will be piped to Minot and other communities in northwestern North Dakota. Manitoba fears the potential transfer of harmful material into its waters through NAWS.

Preliminary findings released late last year said the project poses little risk to Canadian waters under any of four treatment options.

Federal officials ultimately will choose one of the four alternatives. Bureau of Reclamation spokeswoman Patience Hurley said the agency will consider the public comments.

NAWS has been under construction since 2002. The environmental study ordered by U.S. District Judge Rosemary Collyer is the result of an October 2002 lawsuit filed in Washington by Manitoba. Only construction unrelated to treatment can continue with the judge's permission.