Hello @kingtidemedia,
For Blanco theme you need edit the file blanco/woocommerce/single-product/product-image.php, find the line 41 and after the code src="<?php echo etheme_get_image( $imgId, $mainWidth, $mainHeight, $crop ) ?>"
add this line alt="<?php echo get_post_meta($imgId, '_wp_attachment_image_alt', true)?>"
Thank you.
Regards,
Eva Kemp.