Set an environment variable in .htaccess and retrieve it in PHP

I am trying to set an environment variable in an .htaccess file and retrieve it in PHP. I've looked through a bunch of other threads here on SO but everything I've tried so far has failed.

I've added this line to the .htaccess file:

SetEnv SPECIAL_PATH /foo/bin

I have tried retrieving this value using the getenv() PHP function:

<?php $specialPath = getenv('SPECIAL_PATH'); ?>

I have runned phpinfo() to see the list of available environment variables, SPECIAL_PATH is not there. I am puzzled as to why this is not working.

Thank you!