All of the design requirements specified in this article, except
for those also required by federal, state or county law or regulation,
may be waived by the Board if the deviation or alternative design
is found to be reasonable and within the general purpose and intent
of this chapter and its provisions, and if the literal enforcement
of the specific provision from which a waiver is requested is found
to be impracticable or will exact undue hardship upon the developer
because of peculiar conditions pertaining to the land in question.