Texas Natural Resource Conservation Commission
                     Interoffice Memorandum

To:  Duncan Stewart, New Source Review Division, Office of Air
Quality
Date:  October 15, 1996
Through:  David Duncan, Senior Staff Attorney, Legal Division
From:  Laura Rowan, Staff Attorney, Legal Division
Subject:  Minimum Distance Requirements in Standard Exemptions 106
and 118, 30 TAC 116.211

Issue No. 1

Whether extending a vent line to at least 100 feet from the areas
or structures listed in section (b) of Standard Exemption 106
satisfies the distance requirement in Standard Exemption 106 if
portions of the facility or change from which the vent line is
extended are located less than 100 feet from such areas or
structures.  

Answer

The entire facility or change, including vent lines, must be
located at least 100 feet from the areas or structures listed in
section (b) of Standard Exemption 106 in order to satisfy the
minimum distance requirement in Standard Exemption 106.

Discussion

Standard Exemption 106 provides an exemption from permitting
requirements for facilities or physical or operational changes to
facilities, which satisfy certain listed conditions.  Among those
conditions is the following distance requirement:

(b)  The _facilities or changes_ shall be located at least 100 feet
from any recreational area or residence or other structure not
occupied or used solely by the owner or operator of the facilities
or the owner of the property upon which the facilities are located.
(emphasis added)

This condition requires that entire facilities or changes meet the
100 foot distance requirement.  All portions of a facility or
change, including vent lines, must be located at least 100 feet
from a recreational area, residence or other structure not occupied
or used solely by the facility owner or operator or the owner of
the property upon which the facilities are located in order to
qualify for Standard Exemption 106.  

Issue No. 2

Whether extending a vent line to at least 100 feet from any off-
plant receptor satisfies the distance requirement in section (b) of
Standard Exemption 118 if the facility or change from which the
vent line is extended is located less than 100 feet from off-plant
receptors.

Answer

A facility or change located within 100 feet of an off-plant
receptor can satisfy the distance requirement in section (b) of
Standard Exemption 118 if vent line emissions and all other
emission points are located at least 100 feet from any off-plant
receptor.

Discussion

Standard Exemption 118 provides an exemption from permitting
requirements for facilities, or physical or operational changes to
a facility, that satisfy certain conditions, including the
following minimum distance requirement:

(b)  _Emission points_ associated with the facilities or changes
shall be located at least 100 feet from any off-plant receptor. 
(emphasis added)

Unlike the distance requirement in Standard Exemption 106 discussed
in Issue No. 1 above, the distance requirement in Standard
Exemption 118 does not dictate that the entire facility or the
entire change be sited at least 100 feet from any off-plant
receptor.  Only "emission points" must be at least 100 feet from
off-plant receptors.  Given that the rule does not require that
fugitive emissions, which are not discharged from a single point,
meet the minimum distance requirement, portions of the facility
from which fugitive emissions emanate can be located within 100
feet from off-plant receptors.  Portions of the facility that do
not have emission points can be located within 100 feet from off-
plant receptors.  Accordingly, a facility located within 100 feet
of off-plant receptors could meet Standard Exemption 118's minimum
distance requirement by extending a vent line away from off-plant
receptors if no portions of the facility with emission points are
within 100 feet of off-plant receptors.