American Water Works Company (NYSE:AWK) is expanding in Virginia.

On Thursday, the nation's largest publicly traded U.S. water and wastewater utility company announced plans to purchase wastewater utility Dale Service Corporation.

Dale Service provides wastewater collection and treatment services to approximately 20,000 customers in the Dale City portion of Virginia's Prince William County, operating two wastewater treatment plants with a combined capacity of 9.2 million gallons per day.

Assuming regulatory approval of the purchase, slated to close in the second half of this year, AWW will pay approximately $27.7 million for Dale Service.

AWW is already the largest investor-owned water utility in Virginia. This deal would give it a toehold, as well, in the Virginian wastewater services market.

CEO Jeff Sterba noted in a statement that the Dale Service purchase is "an excellent fit with our Virginia operations, as it allows us to create greater efficiency and economies of scale in providing wastewater service to an area where we already provide water service to customers."

Investors seemed to agree. American Water Works shares climbed 0.9% in Thursday trading, closing at $42.13.