HCA is a federally mandated safety initiative that creates workable and effective programs to promote better solutions for pipeline integrity management.
HCA is qualified by an area in which a large number of population resides at a given moment or time frame that would be affected by an event such as blast, leak, or damage to pipeline.
An outside area that is occupied by twenty (20) or more persons on at least fifty (50) days in any twelve (12) months (the days need not be consecutive). (Examples include, but are not limited to, beaches, playgrounds, recreational facilities, camping grounds, outdoor theatres, stadiums, recreational areas near a body of water, or areas outside a rural building such as a religious facility); or
A building that is occupied by twenty (20) or more persons on at least five (5) days a week for ten (10) weeks in any twelve month period. (The days and weeks need not be consecutive). (Examples include, but are not limited to, religious facilities, office buildings, community centers, general stores, 4-H facilities, or roller skating rinks); or
A facility occupied by persons who are confined, are of impaired mobility, or would be difficult to evacuate. Examples include but ar not limited to hospitals, prisons, schools, day-care facilities, retiremetnt facilites or assisted-living facilities.
This act comes by use of the Class 3/4 location language in 49 CFR 192.5 which uses the concept of "well defined" area used by at least 20 persons 5 days per week for 10 weeks per year or area's used by at least 20 persons on 50 days in a calendar year. This also covers buildings in a defined HCA as 20 buildings within the buffer.
The 20/20 rule is graded on a pressure vs. diameter "r=0.69* (square root of (p*d2))" to create a centerline and radius of where a facility or HCA lies. This calculation has buffered of 300, 660, or 1000 feet by the 192 ruling. To cover all bases some HCA datasets radii a 1500' buffer centerline to the pipeline or HCA to pipeline.
HCA does not require you to an exhaustive search, only a good faith effort.
