Here is a timeline as best I can figure out:

Leak happened on February 7th and spilled 1200 gallons of raw sewage into the very upper end of Manklin Creek.

OPA found out about the leak and included a notice in their weekly news email on February 10th and posted a news item on the OPA Website.

Worcester County issued a press release on February 12th.

Worcester County and/or the Ocean Pines Water & Sewer Service Area specifically failed to provide adequate notice to those potentially impacted.

The Service Area alerted the State of Maryland about the leak on the day it happened, February 7th. The Service Area should have immediately contacted the Worcester County public relations department and had them issue a press release on February 7th.

As Tom Hemkick suggested, had this been during the summer, there could have been a far greater risk to humans due to the delay in notification.