SouthWest Water Stockholders to Vote on Merger Agreement

LOS ANGELES, July 6, 2010– SouthWest Water Company (Nasdaq:SWWC) today announced that it will hold its 2010 Annual Meeting of Stockholders on August 6, 2010 and will commence the mailing of the notice of meeting and the definitive proxy statement to stockholders on or before July 9, 2010. Matters to be voted on at the annual meeting include the adoption of the merger agreement announced on March 3rd whereby institutional investors advised by J.P. Morgan Asset Management and Water Asset Management, LLC have agreed to acquire the company and stockholders will be entitled to receive $11 per share.

The closing of the merger is conditioned upon approval by the majority of the combined voting power of the outstanding common stock and preferred stock, voting as a single class, as well as the receipt of various regulatory approvals and other conditions. Should the stockholders approve the proposal at the meeting and the other conditions are satisfied, the company anticipates the transaction will close early in the fourth quarter of this year.

Holders of record of the company’s common stock and preferred stock as of the close of business on June 14, 2010 will be entitled to vote at the meeting. SouthWest Water’s board of directors has unanimously determined that the merger agreement is in the best interests of SouthWest Water and its stockholders, and recommends that stockholders vote “FOR” adoption of the merger agreement. Stockholders are encouraged to read the company’s proxy materials in their entirety as they provide, among other things, a detailed discussion of the process that led to the merger agreement and reasons behind the board of directors’ unanimous recommendation. Stockholders with questions about the merger agreement, or who need assistance in submitting their proxy or voting their shares should contact SouthWest Water’s proxy solicitor, Morrow & Co., LLC toll-free at (800) 607-0088 or at (203) 658-9400.

About SouthWest Water

SouthWest Water Company provides a broad range of operations, maintenance and management services, including water production, treatment and distribution; wastewater collection and treatment; customer service; and utility infrastructure construction management. The company owns regulated public utilities and also serves cities, utility districts and private companies under contract. More than a million people in nine states depend on SouthWest Water for high-quality, reliable service. Additional information may be found on the company’s website: www.swwc.com.

Forward-Looking Statements

This document contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. These statements, including, but not limited to, statements and expectations relating to the proposed transaction, involve risks and uncertainties. These expectations may differ due to a variety of factors. More detailed information about these factors is contained in the company’s filings with the Securities and Exchange Commission, including under the caption “Risk Factors” in the company’s 2009 Annual Report on Form 10-K. The company assumes no obligation to update these forward-looking statements to reflect any change in future events.

Additional Information

In connection with the proposed transaction, SouthWest Water has filed a proxy statement with the Securities and Exchange Commission (SEC). Before making any voting or investment decision, investors and security holders are urged to carefully read the entire proxy statement and any other relevant documents filed with the SEC, as well as any amendments or supplements to those documents, because they will contain important information about the proposed transaction. A definitive proxy statement will be sent to stockholders in connection with the proposed transaction. Investors and security holders may obtain a free copy of the proxy statement and other documents filed at the SEC’s website at http://www.sec.gov. The proxy statement and such other documents may also be obtained at no cost from SouthWest Water by directing the request to SouthWest Water Company, 624 S. Grand Avenue, Suite 2900, Los Angeles , CA, 90017, Attention: Shareholder Services.

The company and its directors, executive officers and other members of its management and employees may be deemed to be participants in the solicitation of proxies from the security holders of the company in connection with the proposed transaction. Information concerning the special interests of these directors, executive officers and other members of the company’s management and employees in the proposed transaction is included in the company’s proxy statement referenced above. Information regarding the company’s directors and executive officers is also available in its Annual Report on Form 10-K for the year ended December 31, 2009, which is filed with the SEC. These documents are available free of charge at the SEC’s website at www.sec.gov and from the company at the address provided above.

For Further Information:

CONTACT: DeLise Keim

VP Corporate Communications

213.929.1846

SouthWest Water Company

624 S. Grand Ave., Suite 2900

Los Angeles, CA 90017

www.swwc.com

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