<p>POWER OF ATTORNEY<br />
<br />
KNOW ALL PERSONS BY THESE PRESENTS that WEST STREET GLOBAL<br />
INFRASTRUCTURE PARTNERS III, L.P. (the "Company") does hereby<br />
make, constitute and appoint each of Jamison Yardley and<br />
Jennifer Lee, acting individually, its true and lawful attorney,<br />
to execute and deliver in its name and on its behalf whether the<br />
Company is acting individually or as representative of others,<br />
any and all filings required to be made by the Company under the<br />
Securities Exchange Act of 1934, (as amended, the "Act"), with<br />
respect to securities which may be deemed to be beneficially<br />
owned by the Company under the Act, giving and granting unto<br />
each said attorney-in-fact power and authority to act in the<br />
premises as fully and to all intents and purposes as the Company<br />
might or could do if personally present by one of its authorized<br />
signatories, hereby ratifying and confirming all that said<br />
attorney-in-fact shall lawfully do or cause to be done by virtue<br />
hereof.<br />
<br />
THIS POWER OF ATTORNEY shall remain in full force and effect<br />
until the earlier of (i)<br />
August 14, 2022 and (ii) such time that it is revoked in writing<br />
by the undersigned; provided that in the event the<br />
attorney-in-fact ceases to be an employee of the Company or its<br />
affiliates or ceases to perform the function in connection with<br />
which he/she was appointed attorney-in-fact prior to such time,<br />
this Power of Attorney shall cease to have effect in relation to<br />
such attorney-in-fact upon such cessation but shall continue in<br />
full force and effect in relation to any remaining<br />
attorneys-in-fact. The Company has the unrestricted right<br />
unilaterally to revoke this Power of Attorney.<br />
<br />
This Power of Attorney shall be governed by, and construed in<br />
accordance with, the laws of the State of New York, without<br />
regard to rules of conflicts of law.<br />
<br />
IN WITNESS WHEREOF, the undersigned has duly subscribed these<br />
presents as of August 14, 2019.<br />
<br />
<br />
WEST STREET GLOBAL INFRASTRUCTURE PARTNERS III, L.P.<br />
<br />
By: Broad Street Infrastructure Advisors III, L.L.C.,<br />
its General Partner<br />
<br />
<br />
<br />
<br />
<br />
<br />
By: William Y. Eng<br />
Name: William Y. Eng<br />
Title: Attorney-in-Fact</p>