Control of adverse effects.
San Antonio City Code § 16-405
in effectSec. 16-405. - Control of adverse effects.
(a) General requirements. Subsection 16-404(c) notwithstanding, extraction activities and facilities, and reserve tracts, shall not be subject to the requirements of chapter 21, article III of this Code, provided such operations have secured and are in compliance with the necessary permits and the requirements of this section. Extraction activities and blasting shall be conducted according to this section.
(b) Airblast (noise) limits. For the purpose of this article, the air overpressure and related noise generated by the use of explosives in excavation activities shall be measured by the airblast created thereby. Airblast shall not exceed the maximum limits listed below at the location of any dwelling, public building, school, church, or community or institutional building outside the permit area, except as provided in subsection (f) of this section.
Lower frequency limit of measuring system, in Hz (plus-minus 3 dB) | Maximum level, in dB
0.1 Hz or lower—flat response * | 134 peak
2 Hz or lower—flat response | 133 peak
6 Hz or lower—flat response | 129 peak
C-weighted—slow response * | 105 peak dBC
* Only when approved by the regulatory authority.
(c) Monitoring requirement.
(1) The operator shall conduct monitoring to ensure compliance with the airblast standards. Airblast measurement of blasts must be performed to the extent required by subsection 16-404(f).
(2) The measuring systems shall have an upper-end flat-frequency response of at least two hundred (200) Hz.
(d) Flyrock. Flyrock traveling in the air or along the ground shall not be cast from the blasting site beyond the area under the control of the operator.
(e) Ground vibration.
(1) General. In all blasting operations, except as otherwise authorized in subsection (f) below, the maximum ground vibration shall not exceed the values illustrated in Figure 1, below. The maximum ground vibration for protected structures listed in subsection (2)a. below shall be established in accordance with the maximum peak-particle-velocity limits as shown below.
(2) Maximum peak particle velocity.
a. The maximum ground vibration shall not exceed the following limits at the location of any dwelling, public building, school, church, or community or institutional building outside the area under the control of the operator:
[image omitted; see the official code]
* When plaster is used in construction of nearest structure.
b. A seismographic record including both particle velocity and vibration-frequency levels shall be maintained for each blast to the extent required by subsection 16-404(f).
(f) The maximum airblast and ground vibration standards of this section shall not apply at the following locations:
(1) At structures owned by the permittee and not leased to another person;
(2) At structures owned by the permittee and leased to another person, if a written waiver by the lessee has been obtained.
(Ord. No. 87907, § 5, 6-4-98)
Source: City of San Antonio, City Code, City Charter and Unified Development Code (Municode Library, library.municode.com)URL: https://library.municode.com/tx/san_antonio/codes/code_of_ordinances?nodeId=PTIICO_CH16LIBURE_ARTXIVEXOPRE_S16-405COADEFFetched: 10/27/2026