(Changes sourcing to company)

Nov 1 (Reuters) - Wastewater treatment systems provider Evoqua Water Technologies Corp said on Wednesday its initial public offering was priced at $18 per share, raising about $500 million.

The 27.78-million share offering was priced at the midpoint of the expected range of $17 to $19 and is expected to debut on the New York Stock Exchange under the symbol "AQUA" on Thursday.

Evoqua is the largest North American provider of water treatment solutions. Based in Pittsburgh, Pennsylvania, it makes filtration products used for removing impurities from water, rather than neutralizing them through the addition of chemicals.

Evoqua has benefited from several global trends as population growth, increasing levels of urbanization and more stringent regulations have been driving demand for cleaner and sustainable waste streams.

Private investment firm AEA owns 58.5 percent of Evoqua's common stock and plans to own between 43 percent and 40 percent after the IPO.

Credit Suisse, J.P. Morgan and RBC Capital Markets are among top underwriters to the IPO. (Reporting by Nikhil Subba in Bengaluru; Editing by Sandra Maler)