Drupal - How to remove url alias when node is deleted

You can use hook_node_delete:

function hook_node_delete($node){
    // Delete alias.
    $path = path_load(
      array('source' => 'node/'.$node->nid)
    );

    path_delete($path['pid']);
}

You can update aliases here, or on the node

/admin/config/search/path

or bulk update a whole bunch here

/admin/config/search/path/update_bulk

based on an alias pattern change set here

/admin/config/search/path/patterns

I imagine the reason it "Seems" like an alias didn't delete is because it have forwarding to another alias in a sort of chain. Drupal does clean up alaises on content delete, ou can do a simple test and see it happen. But if you have alaises chained it only seems to delete the final alais and leave the others. I think if you update you "update actions" you can minimize the number of extra alaises created.

Go here and find the section called "Update action" /admin/config/search/path/settings

You have three choices of what to do when an alais changes

• Do nothing. Leave the old alias intact.
• Create a new alias. Leave the existing alias functioning.
• Create a new alias. Delete the old alias.

Also based on there advice "Considering installing the Redirect module to get redirects when your aliases change."

I hope this helps ans isn't off base but I faced similar issue on a site with 500k items and the clean up was a serious issue. Best of luck!