config-file-load.php

    $application = new \Zend_Application(
        APPLICATION_ENV,
        array(
        'config' => array (
            APPLICATION_PATH . '/configs/application.ini',
            APPLICATION_PATH . '/configs/local.ini'
            )
        )
    );
    $application->bootstrap()
                ->run();

$application_config = new Zend_Config_Ini(
    APPLICATION_PATH . '/configs/application.ini',
    APPLICATION_ENV
);

$local_config = new Zend_Config_Ini(
    APPLICATION_PATH . '/configs/local.ini',
    APPLICATION_ENV
);

// might be the other way around to this TBH
$config = $application_config->merge($local_config);