Exhibit 3

Joint Filing Agreement

The undersigned parties hereby agree to the joint filing of the Statement on Schedule 13D filed herewith, and any amendments hereto, relating to the Common Units of Dominion Midstream Partners, LP, with the Securities and Exchange Commission pursuant to Rule 13d-1(k).

Dated: December 9, 2016

DOMINION RESOURCES, INC.
a Virginia corporation
By:	/s/ Mark O. Webb
	Mark O. Webb
	Senior Vice President, General Counsel and Chief Risk Officer
DOMINION COVE POINT, INC. a Virginia corporation
By:	/s/ Mark O. Webb
	Mark O. Webb
	Senior Vice President and General Counsel
DOMINION MLP HOLDING COMPANY, LLC
A Delaware limited liability company
By:	/s/ Mark O. Webb
	Mark O. Webb
	Senior Vice President and General Counsel
DOMINION MLP HOLDING COMPANY II, INC.
A Virginia corporation
By:	/s/ Mark O. Webb
	Mark O. Webb
	Senior Vice President and General Counsel
DOMINION QUESTAR CORPORATION
A Utah corporation
By:	/s/ Mark O. Webb
	Mark O. Webb
	Senior Vice President and General Counsel
QPC HOLDING COMPANY
A Utah corporation
By:	/s/ Mark O. Webb
	Mark O. Webb
	Senior Vice President and General Counsel