Friendswood says it won't pay bill for $377,000

City officials in Friendswood are disputing a $377,000 invoice from the city of Houston for costs to operate the Southeast Water Purification Plant.

Friendswood is a part owner of the plant, which treats water for southeast Houston and several other area cities, including Nassau Bay, Webster, South Houston and Pasadena.

Friendswood has invested about $20 million in the plant, which began operating in 1990, and gets about 80 percent of its water from the facility, for which it pays about $1 million a year.

This spring, Houston sent Friendswood an invoice for $296,000 for 2009 and $81,000 for 2010 for added costs to operate the plant - numbers Friendswood believes are wrong.

"We are saying that we do not believe the calculations," said Caz Hamidian, Friendswood's director of public works.

Friendswood and the other smaller cities that received invoices have hired an attorney to represent them in the dispute and have informed Houston they don't intend to pay.

Alvin Wright, spokesman for Houston's department of public works, said he believed the dispute had been resolved, but did not discuss specifics of how Houston arrived at its figures.

Houston billed its partners for personnel costs that cannot be verified at this point, said Wayne Sabo, Webster's city manager. Chris Reed, Nassau Bay's city manager, said Houston missed its contractual obligation to bill the cities for the additional costs within 90 days of the end of the fiscal year.

"We had already calculated our budget," Reed said.

In his reply to Houston, Reed claimed Houston had failed to perform the audit required to validate any additional operating costs.