DES MOINES — The Iowa Economic Development Authority board approved tax rebates for up to $300,000 for the Hydrite Chemical Co. plant in Waterloo.

Hydrite is involved in chemical distribution, food and dairy sanitation, food ingredients, organic processing, water treatment and other related businesses. The company has operations in California, Iowa, Illinois, Indiana and Wisconsin.

It sought tax breaks for a planned expansion of the Waterloo facility to increase its production capacity.

During a telephone meeting Thursday hosted at the authority’s Des Moines headquarters, authority board Chairman Dave Bernstein said the $8.88 million expansion is expected to bring an additional nine jobs to Hydrite and help the company retain one.

The state incentives for the deal include $64,500 in sales, service or use tax refunds and $234,700 in tax credits plus an additional $750 tax credit for research activities.

The project is expected to cost $1.1 million in site preparation and another $1.1 million for building construction. The equipment for the expansion is $6.7 million, according to state documents.

Construction is expected to begin in the first quarter of 2013, and production is expected to begin at the end of 2013.

In other business, the board approved a 150-acre expansion of an enterprise zone in Sioux City.

Businesses that set up inside the zone’s borders can get state and local tax breaks for doing so as long as they meet some additional requirements.

The section approved by the board covers a roughly rectangular area bordered by 29th and 19th streets on the north and south and Summit and Jackson streets west and east.