ENMAX Power Corporation - ENMAX No. 5 Substation Post-Construction Comprehensive Sound Level Survey and Class A2 Adjustment January 22, 2021 ...
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Decision 26165-D01-2021 ENMAX Power Corporation ENMAX No. 5 Substation Post-Construction Comprehensive Sound Level Survey and Class A2 Adjustment January 22, 2021
Alberta Utilities Commission
Decision 26165-D01-2021
ENMAX Power Corporation
ENMAX No. 5 Substation Post-Construction Comprehensive Sound Level Survey and
Class A2 Adjustment
Proceeding 26165
Application 26165-A001
January 22, 2021
Published by the:
Alberta Utilities Commission
Eau Claire Tower
1400, 600 Third Avenue S.W.
Calgary, Alberta T2P 0G5
Telephone: 310-4AUC (310-4282) in Alberta
1-833-511-4AUC (1-833-511-4282) outside Alberta
Email: info@auc.ab.ca
Website: www.auc.ab.ca
The Commission may, within 30 days of the date of this decision and without notice, correct
typographical, spelling and calculation errors and other similar types of errors and post the
corrected decision on its website.Alberta Utilities Commission
Calgary, Alberta
ENMAX Power Corporation
ENMAX No. 5 Substation Decision 26165-D01-2021
Post-Construction Comprehensive Sound Level Survey Proceeding 26165
and Class A2 Adjustment Application 26165-A001
1 Decision summary
1. In this decision, the Alberta Utilities Commission approves a request by
ENMAX Power Corporation (EPC) for a Class A2 adjustment (also called ambient monitoring
adjustment) for the nighttime permissible sound level (PSL) at a noise receptor (R1) close to the
ENMAX No. 5 Substation; confirms that the associated post-construction comprehensive sound
level (CSL) survey was conducted in accordance with the requirements of Rule 012: Noise
Control; finds ENMAX No. 5 Substation compliant with Rule 012 and finds Condition 5 of
Permit and Licence 26133-D01-2020 to be satisfied.
2 Introduction
2. EPC, pursuant to Permit and Licence 26133-D01-2020, 1 is the operator of the
ENMAX No. 5 Substation, which is located within the southeast quarter of Section 15,
Township 24, Range 1, west of the Fifth Meridian, at municipal address 302 10th Avenue S.E. in
the city of Calgary.
3. Condition 5 of Permit and Licence 26133-D01-2020 for the ENMAX No. 5 Substation
states:
ENMAX shall conduct a post-construction comprehensive noise survey in accordance
with the requirements of Rule 012: Noise Control, and shall submit this noise survey to
the Commission by February 1, 2021. ENMAX shall implement additional noise
measures, if required, to bring the substation into compliance with Rule 012 thereafter.
4. In August 2020, EPC conducted a post-construction CSL survey for the
ENMAX No. 5 Substation. On December 10, 2020, EPC submitted a report describing the results
of the CSL survey. As part of its submission, EPC also applied for a Class A2 adjustment based
on the results of the CSL survey. 2 EPC’s submission was registered as Application 26165-A001
in Proceeding 26165.
5. The Commission issued information requests (IRs) on December 17, 2020 seeking
weather data and low frequency noise (LFN) data. The Commission considers the close of record
to be January 7, 2021, when EPC responded to the Commission’s IRs.
1
Substation Permit and Licence 26133-D01-2020, Proceeding 26133, Application 26133-A001,
December 4, 2020.
2
Exhibit 26165-X0001, 2020-12-10-EPC-No. 5 Sub A2 Adjustment Application.
Decision 26165-D01-2021 (January 22, 2021) 1ENMAX No. 5 Substation
Post-Construction Comprehensive Sound Level Survey
and Class A2 Adjustment ENMAX Power Corporation
3 Post-construction comprehensive sound level survey
6. The CSL survey was conducted at the Bell Block building (R1) from August 24 to
August 28, 2020. The use of R1 is consistent with the latest noise impact assessment (NIA)
prepared for the ENMAX No. 5 Substation (the 2010 NIA). 3 In the 2010 NIA, R1 was identified
as the most affected dwelling.
7. The locations of the ENMAX No. 5 Substation and R1 are shown in the following figure:
8. Sound level measurements were collected using a Brüel & Kjær (B&K) Type 2250
Class 1 sound level meter, which was calibrated immediately prior to and after the CSL survey
using a B&K Type 4231 field calibrator. EPC provided calibration certificates for the sound
level meter and the calibrator. For the duration of the CSL survey, the sound level meter
recorded energy equivalent sound levels (Leq) at one-minute intervals in units of A-weighted
decibels (dBA) and C-weighted decibels (dBC). Audio data were also recorded continuously by
the sound level meter. A portable meteorological station measured wind speed and wind
direction concurrently with the sound level measurements.
9. To calculate CSL at R1, EPC performed an isolation process to exclude invalid or
abnormal data from the measured sound levels. Invalid data, consisting primarily of voices,
3
Exhibit 0002.00.EPC-708, Appendix 5 - with Sub NIA Report, Proceeding 708.
Decision 26165-D01-2021 (January 22, 2021) 2ENMAX No. 5 Substation
Post-Construction Comprehensive Sound Level Survey
and Class A2 Adjustment ENMAX Power Corporation
emergency vehicle sirens, construction noise and wind-induced noise, were identified using
the audio recordings. In addition, sound level data recorded when wind speeds exceeded
three metres per second were removed to exclude contamination from sounds caused by higher
wind speeds.
10. Based on review of the audio recordings, EPC noted that sources from the
ENMAX No. 5 Substation were inaudible during the CSL survey.
11. EPC used valid sound level data to calculate the CSL for each daytime and nighttime
period captured by the survey, as well as the overall daytime and nighttime CSL for the full
duration of the survey. CSL values established by EPC are summarized in the table below, along
with the number of valid minutes during each daytime and nighttime period. EPC noted that the
CSL at R1 is generally consistent throughout the daytime and nighttime hours.
Table 1. Results of the CSL survey
Daytime1 Nighttime2
Date
CSL (dBA) Valid Minutes CSL (dBA) Valid Minutes
August 24, 2020 61.6 615 59.5 539
August 25, 2020 61.8 873 61.3 535
August 26, 2020 62.5 812 59.9 534
August 27, 2020 62.1 881 60.4 540
August 28, 2020 62.2 410 –3 –3
Overall 62.0 3591 60.3 2148
1. Daytime: Defined as the hours from 7 a.m. to 10 p.m.
2. Nighttime: Defined as the hours from 10 p.m. to 7 a.m.
3. “– ” indicates no measurement for that period.
12. To assess Rule 012 compliance for the ENMAX No. 5 Substation, EPC compared
measured CSLs to PSLs from the 2010 NIA. The 2010 NIA used Table 1 of Rule 012 to
establish assumed ambient sound levels (ASLs) at R1 and then used these assumed ASLs to
establish PSLs. Because the 2010 NIA did not consider A2 adjustments to the PSLs, these PSLs
will hereafter be referred to as unadjusted PSLs.
13. Table 2 presents the results of EPC’s compliance assessment using unadjusted PSLs. This
assessment indicates the measured daytime CSL is less than the unadjusted daytime PSL, but the
measured nighttime CSL exceeds the unadjusted nighttime PSL.
Table 2. Compliance assessment using unadjusted permissible sound levels
Daytime Nighttime
Receptor Measured Unadjusted Compliant with Measured Unadjusted Compliant with
CSL (dBA) PSL (dBA) unadjusted PSL? CSL (dBA) PSL (dBA) unadjusted PSL?
R1 62.0 66 Yes 60.3 56 No
Decision 26165-D01-2021 (January 22, 2021) 3ENMAX No. 5 Substation
Post-Construction Comprehensive Sound Level Survey
and Class A2 Adjustment ENMAX Power Corporation
14. EPC submitted that the measured CSL exceeded the unadjusted nighttime PSL because
the assumed nighttime ASL is not representative of the actual ASL at R1. EPC noted the
assumed ASL does not adequately account for dominant sound sources in the area (e.g., road
traffic and rail traffic) and, as such, the assumed nighttime ASL at R1 is too low to be
representative of the ambient sound environment at R1. Because the unadjusted PSL is
established with reference to the assumed ASL (i.e., the unadjusted PSL is five dBA greater than
the assumed ASL), EPC submitted the unadjusted nighttime PSL is also too low.
15. To support its position that road and rail traffic are the primary contributors to sound
levels at R1, EPC submitted the results of a traffic noise study prepared for the area surrounding
R1. EPC’s traffic noise study has two components:
a. EPC reviewed the data collected during the CSL survey and observed that noise from rail
traffic is consistent throughout daytime and nighttime periods and that train by-passes
increased sound levels from two to six dBA, particularly during the nighttime period. As
such, EPC concluded that the nearby rail line is a significant contributor to the ASL at R1.
b. EPC monitored traffic volumes along MacLeod Trail S.E., and presented hourly
measured sound levels and traffic volumes in a single figure. This figure demonstrates a
correlation between measured sound levels and the number of vehicle by-passes on
MacLeod Trail S.E. As such, EPC concluded that MacLeod Trail S.E. is a significant
contributor to the ASL at R1.
16. Based on the above analysis, EPC submitted that an A2 adjustment should be applied to
the nighttime PSL to account for the urban soundscape affecting R1.
17. Because the CSL survey demonstrated that the ENMAX No. 5 Substation is compliant
with the unadjusted daytime PSL, EPC did not apply for an A2 adjustment to the daytime PSL.
18. In response to the Commission’s IRs, EPC analyzed LFN and concluded there was no
LFN condition present during the CSL survey. 4
4 Class A2 adjustment
19. Rule 012 requires that an A2 adjustment be determined based on the representative ASL.
The representative ASL must be measured/determined in the absence of noise contributions from
energy-related facilities. Because it was not feasible to measure directly the ASL at R1 in the
absence of energy-related facilities (i.e., it was not feasible to shut down the
ENMAX No. 5 Substation for the purposes of collecting noise measurements), EPC used a
computer model to predict the noise contribution from the ENMAX No. 5 Substation at R1 in the
absence of other sources, and then subtracted this value from the measured CSL to estimate the
representative ASL.
20. The computer noise model for the ENMAX No. 5 Substation was developed using
near-field measurements of individual noise sources collected on August 26, 2020. The computer
model reflected an operating scenario with cooling fans active on all transformers, which EPC
4
Exhibit 26165-X0006, 2021-01-07-EPC Responses to AUC IRs, PDF pages 4 and 5.
Decision 26165-D01-2021 (January 22, 2021) 4ENMAX No. 5 Substation
Post-Construction Comprehensive Sound Level Survey
and Class A2 Adjustment ENMAX Power Corporation
characterized as the worst-case operating scenario for the ENMAX No. 5 Substation
(i.e., maximum noise emissions).
21. EPC used the representative ASL (calculated using the approach described in the
previous paragraphs) and Figure 1 of Rule 012 to determine an A2 adjustment and A2-adjusted
nighttime PSL for R1.
22. The A2 adjustment and the A2-adjusted PSL for the nighttime period are presented in
Table 3.
Table 3. A2 adjustment and A2-adjusted PSL for the nighttime period
Unadjusted Calculated A2 A2-adjusted Measured Compliant with
Receptor
PSL (dBA) ASL (dBA) adjustment PSL1 (dBA) CSL (dBA) A2-adjusted PSL?
R1
56 56.0 5 61 60.3 Yes
(nighttime)
1. Addition of the A2 adjustment and unadjusted PSL results in the A2-adjusted PSL.
23. The above results indicate that once the PSL is adjusted, the ENMAX No. 5 Substation is
compliant with Rule 012, because the measured nighttime CSL at R1 (60.3 dBA) is less than the
A2-adjusted nighttime PSL (61 dBA).
24. Rule 012 requires that an applicant seeking a Class A2 adjustment include information
relating to the A2 adjustment in its public consultation program. In November 2020, EPC sent a
letter to the residents of R1 and to the owner of the Bell Block building explaining its intention to
apply for an A2 adjustment based on the results of a post-construction CSL survey. No concerns
were raised with the application as a result of EPC’s consultation.
5 Findings
25. The Commission accepts the CSL survey and associated results based on the following:
a. EPC followed the requirements of Rule 012 when collecting data during the CSL survey.
In particular, sound monitoring equipment, deployment procedures, and calibration meet
the requirements of Rule 012.
b. In addition, EPC conducted data analysis in accordance with Rule 012. Invalid data were
appropriately removed through reasonable review procedures.
26. For the reasons detailed in the paragraphs that follow, the Commission also finds that:
a. It was reasonable for EPC to apply for an A2 adjustment given the types of noise sources
and activities that contribute to sound levels at R1.
b. EPC used reasonable methods to determine the representative nighttime ASL at R1.
c. EPC used procedures required by Rule 012 when establishing an A2 adjustment for R1.
Decision 26165-D01-2021 (January 22, 2021) 5ENMAX No. 5 Substation
Post-Construction Comprehensive Sound Level Survey
and Class A2 Adjustment ENMAX Power Corporation
d. EPC consulted relevant stakeholders as required and no concerns or objections about the
A2 adjustment application were raised.
27. First, Rule 012 states that A2 adjustments may be applicable in areas where non-energy
activity influences the ASL. R1 is located directly east of MacLeod Trail and approximately
70 metres south of the Canadian Pacific rail line. According to Rule 012, both MacLeod Trail
and the rail line qualify as heavily travelled. The Commission accepts the conclusions of EPC’s
traffic noise study that MacLeod Trail and the Canadian Pacific rail line dominate sound levels at
R1 and are key contributors to the measured exceedance of the unadjusted nighttime PSL at that
receptor.
28. Based on the foregoing the Commission is satisfied that the assumed nighttime ASL is
not representative of the soundscape at R1. Rather, the ASL is influenced by non-energy noise
sources (MacLeod Trail and the Canadian Pacific rail line) and it is therefore reasonable for EPC
to seek an A2 adjustment for R1.
29. Second, an A2 adjustment must be determined based on the representative ASL, which
must be established without the noise contribution from energy-related facilities. The
Commission accepts that it was not feasible to shut down the ENMAX No. 5 Substation for the
purposes of measuring the ASL at R1 and that EPC therefore had to make use of an alternative
method to establish the representative ASL at that receptor.
30. Section 4.2 of Rule 012 discusses the use of computer models to establish the relative
noise contribution from individual facilities in cases where the contribution from multiple noise
sources may cause measured CSLs to exceed applicable PSLs. 5 In light of Section 4.2 of
Rule 012, the Commission finds that it was reasonable for EPC to establish the representative
ASL at R1 by modelling the noise contribution from the ENMAX No. 5 Substation and then
subtracting this modelled contribution from the measured CSL.
31. Third, the Commission finds that EPC correctly applied procedures from Rule 012 when
establishing an A2 adjustment and A2-adjusted nighttime PSL based on the representative PSL.
Specifically, the Commission finds that an A2 adjustment of five dBA and an A2-adjusted
nighttime PSL of 61 dBA are appropriate for R1.
32. Finally, the Commission is satisfied on the evidence presented that EPC consulted
relevant stakeholders about its A2 adjustment application and there were no objections.
6 Decision
33. The Commission finds that the CSL survey conducted by EPC for the
ENMAX No. 5 Substation fulfills the requirements of Rule 012. The Commission approves
the five dBA A2 adjustment proposed by EPC and has determined that the applicable nighttime
PSL at R1 is 61 dBA.
5
Rule 012: Noise Control, PDF page 24.
Decision 26165-D01-2021 (January 22, 2021) 6ENMAX No. 5 Substation Post-Construction Comprehensive Sound Level Survey and Class A2 Adjustment ENMAX Power Corporation 34. The Commission finds that the ENMAX No. 5 Substation is compliant with Rule 012 at R1 during the daytime and nighttime periods. Consequently, the Commission also considers Condition 5 of Permit and Licence 26133-D01-2020 to be satisfied. 35. Pursuant to sections 14, 15 and 19 of the Hydro and Electric Energy Act, the Commission approves the application and grants EPC an updated permit and licence as set out in Appendix 1 – Substation Permit and Licence 26165-D02-2021 – January 22, 2021 (Appendix 1 will be distributed separately). 36. Substation Permit and Licence 26133-D01-2020 for the ENMAX No. 5 Substation is rescinded. Dated on January 22, 2021. Alberta Utilities Commission (original signed by) Carolyn Hutniak Commission Member Decision 26165-D01-2021 (January 22, 2021) 7
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