The following letter was sent to the ETRPA by Edward M. Knight, AICP, Director of Community Development for Dana Point.
September 30, 1996
City of Irvine
Attention: Mr. Dan Jung, ETRPA
PO Box 19575
Irvine, CA 92713-9575
Subject: Comments Regarding EIR 564; Section 4.4 - Noise
Here are my comments regarding the noise section (Section 4.4) of draft EIR 563. I am also preparing a letter response that will be sent by the City and includes these comments as well as other sections of the draft EIR. That letter will be considered by the City Council at their October 8, 1996 meeting.
1. Characteristics of Sound
Since the EIR is proposing an airport alternative, a discussion is needed regarding jet airplanes and their character of sound and level of magnitude. A quantitative analysis is needed regarding the sound characteristics of Stage II aircraft versus Stage III aircraft. Empirically, what sound benefits will be achieved by this change?
As noted in the Airport Land Use Planning Handbook (Caltrans, 1993), the extent to which future technology can continue to reduce jet-engine noise is uncertain. Most of the noise improvements have been through eliminating older louder jet aircraft. If, due to loading or take-off considerations, a Stage III aircraft remains the same as older noisier aircraft, then the EIR's noise modeling is not accurate and the overall noise level will grow, not decrease.
In regard to sleep interference (pg. 4-169), the EIR fails to document the U.S. Air Force study (Finegold, 1992; referenced in FICON) concluded that approximately 20% of the population can be expected to be awakened by indoor single levels (SEL) of 70 db. This percentage rises to nearly 50% at an SEL of 90db. When background noise levels are low, a single noise having a maximum level as little as 45db may cause people to awaken, particularly if they are not accustomed to such noise.
The airport as proposed will have a dramatic change from the existing sound parameters; while military jet aircraft are noisier, they seldom have evening operations and never have night operations. The dramatic shift in aircraft operations will create a new paradigm for the region, significantly altering the historic noise matrix. Decision-makers need a thorough and complete analysis of this shift in order to weigh the economic benefits of the airport versus the environmental harm caused by this changed noise matrix.
The section on annoyance needs to be expanded to include annoyance factors caused by aircraft operations at an airport. The current description is too general and contains no information on annoyance impacts caused by aircraft operations at an airport. One key factor is that the noise by a jet aircraft creates a feeling of fear or anxiety. Although people may not fear the aircraft noise, they may be apprehensive that the aircraft would crash on their property, and the noise creates this awareness of the aircraft's presence.
This is particularly crucial since the proposed airport will be introducing night operations, and bring commercial jet aircraft to areas of the county which have never experienced the anticipated level of noise operations. It is reasonable to expect that these residences will experience significant impacts, but this potential is not discussed in the draft EIR.
On page 4-171, regarding Single Event Noise Exposure Levels (SENEL), the draft EIR is not entirely accurate that a SENEL value is typically about 10dba higher than L max. According to the Airport Land Use Handbook, for most aircraft noise events, SEL/SENEL is about 5 to 10dba higher than L max; the shorter the noise event is, the closer the two numbers will be. The EIR should be amended to include this information.
In regard to Noise/Land Use Compatibility Standards (pg. 4-174), the Schultz curve is based upon the findings of research on all types of transportation noise. In regard to the airport alternatives, the EIR must include discussion of studies related only to aircraft noise. This other research suggests that aircraft noise is considerably more annoying than highway noise. These studies in combination with local studies regarding the effect of aircraft noise at John Wayne Airport (JWA) clearly show that the predictable effects for aircraft noise can not be explained with the use of the Schultz curve.
Recent developments in the study of aircraft noise from the Federal Government support the research that airports require further noise mitigation, and that previously accepted standards are inadequate to address the unique noise problems created by aircraft noise.
This draft EIR needs to map the 55 db DNL (CNEL) line since this is shown as an area of "moderate impact". Since measures to ensure compatibility will be the responsibility of state or local government in the "moderate impact" areas, the associated measures should be included as mitigation measures. The LRA needs to identify a funding source to aid residents in constructing additional acoustical insulation above the 55 CNEL line.
Once the impact of the Noise Policy is known (which should be September 1996), the LRA should amend the EIR and circulate a supplement indicating the new policy and its environment affects on southern and central Orange County.
One aspect that is basically ignored in the draft EIR is the significant impact from aircraft noise on those areas of Orange County which have never experienced noise impacts as a result of aircraft operations at El Toro. Since the military jet aircraft make a quick left turn from departures on runway 34, all overflights over Tustin, Cowan Heights, and the City of Orange are new flights. These areas will receive the largest and noisiest aircraft (747-200) and the greatest number of night flights, since most cargo flights will use runway 34 for night departures. Residents in Cowan Heights can expect a SENEL change of 86.9db. Since this area can be characterized on a sound chart as a quiet suburban or quiet rural, the change in noise characteristics will be from an average background noise level of 30 to 40db to an SENEL of 86.9db. Even with sound attenuation from a structure, a home with its windows open can expect a SENEL of 71.9db. According to earlier comments from the Finegold study, over 20% of the population can be expected to be awakened by an indoor single level of 70db.
The EIR needs to also document studies which examine a similar impact. A study was done in reaction to flight track changes implemented by the FAA in the New York/New Jersey area. The adverse reaction from the affected areas was substantial, even though the resulted noise level changes were still below the acceptable DNL (CNEL) levels. The draft EIR needs to thoroughly examine this issue and propose mitigation measures. The best approach is to accept a non-aviation reuse plan and eliminate these significant impacts.
According to the draft EIR, the noise analysis for military operations was prepared by using NOISE MAP 6.4, a computer program that includes noise characteristics for both civilian and military aircraft. Explain how NOISE MAP could predict CNEL's for Tustin, Cowan Heights, and the City of Orange. These figures are 41.7, 38.8, and 37.9, respectively. Since the jet aircraft make a left turn after departure on runway 34, it seems inconceivable that the City of Orange would receive even a small CNEL of 37.9.
Why are such small CNEL's figures used on Table 4-30, especially since other tables (4-31 and 4-40) remove noise figures below a certain threshold, apparently since that were deemed to be less than significant.
Since NOISE MAP includes both military and civilian aircraft, why was INM Version 5.01 used for civilian aircraft, and NOISE MAP used only for military aircraft? What is the difference between the two programs, and how can the EIR attempt to compare noise information with two separate programs? The EIR needs to elaborate on this.
It is the City's contention that the EIR should not compare 1994 jet aircraft operations with any proposed aviation alternative. Since the Marine Corp has formally decided that the base will be closed, it formally ceased to exist as a military airport. In other areas of the EIR, such as air quality, a positive impact is documented for the region since the military jet aircraft will be leaving. Yet, under noise impacts, the impacts from the jet aircraft remains as if it would continue indefinitely. Since the EIR recognizes a positive impact in air quality, then it should recognize the positive impact with the removal of noise impacts from military aircraft. The two airport alternatives should be compared to the existing noise environment at the time that they will be implemented. At that time, the impact from military jet aircraft will be eliminated.
On page 4-212, the draft EIR indicates that approaches to runways 25 or 16 are not available due to terrain. This conflicts with Figure 2-5 on page 2-28 and the description of airspace considerations on page 2-27. On those pages,the designated approach and departure for a south and southeast flow indicates that 98.2% of arrivals will be using runway 16. It would appear that the draft EIR inaccurately projects noise impacts since the anticipated arrivals and departures does not match the computer generated noise analysis.
The description of preferential runway system on page 4-214 is not clear. Do C-17 transports land at El Toro? If the do, which runway do they use for departure. Do any transports use runway number 7? If a C-130 is a short runway aircraft, why does it only use runway 34?
On page 4-214, describe how the operational forecasts were determined? Why were the given mix of aircraft chosen and assigned to certain number of flights. Many of the aircraft noted on Table 4-33 are not included on either Figure 4-53 or Figure 4-54. What are the noise characteristics for those aircraft that are not included on the two figures?
Table 4-34 should also include the number of proposed flights by aircraft category, not just the percentage. It is not possible to determine the number of flights by category with the information provided.
Table 4-33 indicated that 2 arrivals will be from military aircraft on runway 16. According to existing runway and flight track utilization, currently no military aircraft use runway 16 for arrivals. Why would the military change that policy in the future?
On page 4-216, it is irrelevant to mention helicopter operations from MCAS Tustin (H) occurring in the North Corridor. MCAS Tustin will be closing in 1997 and all helicopter operations will cease. Further, helicopter operations at Tustin (H) have no connection to the noise created by military operations at El Toro.
On page 4-221, regarding night operations, break down the 172 night operations by runway and type of aircraft. The noise characteristics of aircraft vary greatly, and there should be some understanding of the type of aircraft that will be arriving or departing during the nighttime hours.
On page 4-221, provide CNEL contours for the proposed airport alternatives using NOISE MAP 6.4. This will permit the general public to better understand the differences between the two computer modeling systems.
Regarding SENEL, on page 4-224, as noted earlier, the SENEL difference can be between 5dba to 10dba higher than the Lmax. Therefore the 85 SENEL can result in a 70dba impact in a residence with its windows open. Studies have shown that at least 20% of the population will be awakened by these overflights. Other factors come into play. The existing nighttime noise environment in this area is probably in the range of 30-40dba. These flights represent a new and significant source of noise in an otherwise quiet environment. The draft EIR indicates that approximately ten (10) 747-400 flights will occur each day. Each flight represents a distinctive event which further exacerbates the new noise intrusions. These new night flights represent a new and significant intrusion no only to this area, but all affected areas surrounding the airport. The only way that people will be able to talk or sleep is within their homes, with all windows shut.
Regarding Table 4-39 on page 4-228, some of the CNEL figures need further explanation. For example, the projected CNEL for T1, CH1 and O1 is 51.0, 54.6, and 56.8, respectively. Yet T1 is the closest to the airport and O1 is the farthest away. Further, O1 is outside the 85dba SENEL for a 747-400 as shown on Figure 4-56.
Explain how the CNEL could rise as the receptor is located further away from the airport, and the noisiest receptor (O1) is located outside of the 85dba SENEL for a 747-400. Yet, the receptor that is closest to the airport and clearly in the middle of the 85dba SENEL for a 747-400 (T1) has the lowest CNEL of the three by over 5.8dba.
There are other discrepancies in this table which need further explanation. The receptor OC2 is along the same line AV3 and considerable closer to the landing strip at El Toro, yet the proposed CNEL (60.4db) for both receptors is identical. Even more unusual is receptor LN-1, which is for removed from receptor AV3, barely written the 85 SENEL for a 747-400 and along the same line as AV3. In spite of this it has a CNEL of 60.6, which is .2 higher than AV3. These and other apparent discrepancies bring into question the entire accuracy of Table 4-39. Instead of locating receptors at the extreme edge of the 60 CNEL, receptors should be located along the direct line of the jet aircraft for approaches and departures of jet aircraft in order to gain a more accurate estimate of noise impacts. This table needs to be thoroughly explained and documented to ensure that the information contained in it is accurate.
Regarding the aviation noise summary on page 4-224, it is inappropriate to compare the noise environment for 1994 military jet aircraft to the proposed airport alternatives since the military base will be closing and all military will cease long before the proposed reuse aviation alternative would be implemented. The military jet aircraft leaving creates a positive impact to the local environment in regard to noise, in the same way that removal of the military jet aircraft creates a positive air quality impact to the region. Proposed noise impacts should be compared to the noise environment at the time that the airport would be implemented.
If the LRA continues to make these comparisons, then the use of one computer modeling system should be used in order to create an "apples to apples" comparison. It is not clearly documented that NOISE MAP and INM are comparable and therefore any comparison would be invalid.
Regarding the mitigation measures related to noise, it is inappropriate to delay any meaningful discussion to a point where the development of a 38 MAP civilian airport is a certainty. At this stage of the process, the LRA can weigh the relative impact caused by the airport alternatives versus the non-aviation alternative and decide if a non-aviation alternative not only creates a positive economic impact, but a positive social and environmental impact. The noise mitigation measures contained in the draft EIR already predispose that a civilian airport will be built, and provide no meaningful mitigation in spite of the enormous impact to a significant portion of the entire County of Orange. It is inappropriate to make such an important decision that will affect thousands of people with so little mitigation.
The EIR has also clearly documented that some existing and proposed residential units will be within the proposed 65 CNEL. This is a significant impact and the LRA should not use a Statement of Overriding Consideration on this impact. Since any alternative can be chosen for El Toro, creating or perpetuating impacts is inappropriate.
Further, there is little or no discussion of the residential units that will remain and be utilized as homeless or permanent low income housing. The draft EIR claims that these identical units are outside of the 65 CNEL, but they are so close to the 65 CNEL line that even a slight change in the noise matrix could easily place them into the noise impact zone. There should be mitigation measures to address this potential significant impact.
If you have any questions, please contact me at (714) 248-3567.
Edward M. Knight, AICP
Director of Community Development