Trying to execute a query that contains postgis functions in the where clause

I am running:
Drupal 7.17
Database System = Postgresql / 9.1.6

I have created a hook_views_query_alter function that substitutes
node field values into the filter values I set up with views.

This allows me to use an external database connection to create a view using
node fields as the filter.

This works fine for strings, but I would like to use the postgres && operator and
the ST_* functions to add postgis functionality to the view.

Here is the code inside my hook_views_query_alter function:
$query->where[1]['conditions'][3]['field'] = 'geom';
$query->where[1]['conditions'][3]['value'] = 'ST_AsText(ST_Transform(\'' .$current_node->field_map_extent[LANGUAGE_NONE][0]['geometry'] . '\',900913))';
$query->where[1]['conditions'][3]['operator'] = '&&';

The error I'm getting is:
"SQLSTATE[XX000]: Internal error: 7 ERROR: parse error - invalid geometry LINE 6: ... AND (geom && 'ST_AsText...
^ HINT: "ST" <-- parse error at position 2 within geometry"

I believe this is because the ST_... value has quotes around it when the query is executed.

example query from debugger session
========================
SELECT COUNT(*) AS expression FROM (SELECT 1 AS expression FROM parcels_pugetsound parcels_pugetsound WHERE (( (geom && "ST_AsText(ST_Transform('0103000020E6100000010000000500000086670FF461865EC085233789A2FA4740A5C610748C815EC085233789A2FA4740A5C610748C815EC0492BDC3B0CFF474086670FF461865EC0492BDC3B0CFF474086670FF461865EC085233789A2FA4740',900913))") ))) subquery

This query doesn't run on postgres but if I remove the " around "ST_AsText..." then it works fine.

I can't seem to debug any deeper than:
includes/database/database.inc:line 2140
The line "parent::execute($args);" crashes when I attempt to step into it.

Can I strip off quotes from the value field if the operator field is '&&' ??