Comments on the Draft Subsequent Environmental Impact Report for the North Bayshore Master Plan Project

Diana Pancholi, Senior Planner
City of Mountain View
Community Development Department
Diana.Pancholi@mountainview.gov

February 6, 2023

Re: Draft Subsequent Environmental Impact Report for the North Bayshore Master Plan Project

Dear Ms. Pancholi,

The Sierra Club Loma Prieta Chapter, the Santa Clara Valley Audubon Society and Green Foothills are local environmental organizations with inherent interest in biodiversity, native plants and wildlife, ecosystems and natural resources in open spaces and in urban landscapes. We have engaged in planning and conservation efforts in North Bayshore and Shoreline Park for many years. We continue to have a strong interest in the way the community develops and the impacts of the development on the natural environment and the species that share it with us. We have reviewed the Draft Subsequent Environmental Impact Report (DSEIR) for the North Bayshore Master Plan Project (NBMPP, Project) and submit the following comments.

1) Project Description

In our Scoping Comments on the NOP, we asked for the Vision for North Bayshore (described on page 5 of the North Bayshore Precise Plan¹ , NBPP) to be expressed fully to include “innovation and sustainability” as well as “the protection of habitat.” We ask again for all elements of the North Bayshore vision to be reflected in the Project Description section.

2) Approval by Responsible Agencies

The project is immediately adjacent to areas that provide habitat for special-status species (including but not limited to San Francisco Common Yellowthroat at the Charleston Retention Basin and Burrowing owls and Congdon’s tarplant at Shoreline Park). The project also contains the largest heron/egret rookery in the south bay (at Shorebird Way). The California Department of Fish and Wildlife (CDFW) is a Trustee Agency responsible for protecting migratory and nesting birds under California Fish and Game Code and their mandate includes projects and activities that may cause abandonment and/or loss of reproductive efforts through disturbance. Is permitting by CDFW required for project elements in the vicinity of the Charleston Retention Basin, the rookery of Shorebird Way, and Amphitheater Parkway / Shoreline Park?

• Please add the California Department Fish and Wildlife (CDFW) to Table 2.6-1: Required Approval.

3) Utilities

Several new 12 kilovolt (kV) distribution lines are expected to extend from the PG&E’s Ames Substation to the NBMPP area (Section 2.3.5 ). Bird collision with power lines is a recognized threat to colonial nesting colonies and bird populations² , and the risk is greater in the vicinity of water features (such as Stevens Creek) and for larger birds (such as herons and egrets).

• Can construction of new distribution lines that cross Stevens Creek be placed underground and under bridges?
• If undergrounding is found infeasible, please request that PG&E use markers to make the wires more visible to flying birds. A variety of line marking devices, including hanging markers, coils, and aviation marker balls, are commercially available.
• The Project utility upgrades, including distribution lines and supporting facilities, should not create electrocution hazards to raptors³ .

4) Private District Utilities System Option; District Central Plant (DCP)

The DCP is proposed East of 1201 Charleston and potentially could integrate into the building (2.3.5.2). The DCP includes chillers, heat pumps, distribution pumps, cooling towers and air blowers as well as independent backups.

• We are concerned with noise and lighting that this infrastructure and its operations may introduce to the area between Stevens Creek and the heron/egret rookery. Light is especially concerning due to state requirements for industrial facilities. Please describe potential noise and lighting to be used at the DCP, and provide mitigation, including:
  • Use of fixtures with Correlated Color Temperature no more than 2700 Kelvin
  • Use of manual switch for work that is performed at night so that all-night lighting can be minimized.
  • Please consider Section 10, Artificial Light at Night, below.
• The Water Reuse Facility is expected to meet disinfected tertiary recycled water standards as described under Title 22 of the California Code of Regulations. The recycled water would be used for non-potable water demands on-site including toilet flushing, cooling, and irrigation.
  • Can recycled water uses include sustaining permanent and seasonal wetlands at the Charleston Retention Basin and the Eco Gem during dry spells?.

5) Green Building and Emissions Reduction Features (Section 2.3.7)

The groundwater level at North Bayshore, especially in the Shorebird area, is high enough to sustain the wetlands of the Charleston Retention Basin and vegetation around the basin with no irrigation at all. In areas of high water level, native vegetation which is not drought tolerant should be permitted because it allows a more biodiverse ecosystem to thrive with minor, if any, irrigation needs after establishment. Planting drought tolerant vegetation to satisfy Green Building Standards in locations where implementation of the standards is not needed should not be required or encouraged.

• Are there areas within the NBMPP area where the groundwater level is high enough to support vegetation that is not drought tolerant, for example, the eco-gem area?
• On page 29, under Energy Efficient Design, promises “Energy modeling in early design phases to optimize wall-to-wall ratios, thermal performance, and exterior shading.” Is the intention to model window-to-wall ratios?

6) Parking Structures

In our NOP scoping comments, we asked “Please include one alternative scenario with reduced parking… This alternative should also analyze the impact of mitigation strategies that increase the pedestrian, micro-mobility and bicycle capacity, including using Green Streets potentially within the entire North Bayshore Precise Plan area.”

The NBMPP does not offer a Reduced Parking Alternative. Instead, five parking structures are planned to accommodate ±7,274 cars (Table 2.3-5). This adds to existing and planned parking under future buildings, parking structures currently under construction, and existing parking structures. While all new parking structures are of concern, we are especially concerned with the parking structure at Subarea AM1 (Amphitheater).

The NBPP envisioned the vast parking spaces of North Bayshore becoming open space and the area becoming less car-centric. But with so many cars accommodated at North Bayshore, this vision may not be implemented as intently and purposely as we hoped.

• Please provide the footprint of 1) existing and 2) planned parking structures in North Bayshore, in acres.
• Please consider using feasible strategies like parking cash-out⁴ which Stanford, Lockheed, and Genentech⁵ used to avoid building additional parking lots and to reduce automobile use. Stanford may be the best example because it operates under a traffic cap⁶ . Traffic caps work if enforced (for example, using pavement sensors that count vehicles throughput) and controlled (via pricing⁷ ) and feedback systems, such as increasing pricing and fines for exceeding the cap).
• Prior to building each parking structure, please study overall parking demand to evaluate how multi-modal behaviors evolve, and ensure that the added parking is indeed needed.

At the Alta/Huff Parking Structure, Google created a dynamic structure that can accommodate change of use in the future - from parking cars to housing people. This flexibility of re-purpose should be the model for all parking structures:

• New parking structures should be built to allow future re-purposing such as housing.
• New parking structures should be built so as to be able to respond immediately to crisis needs (shelter during major weather events, shelter post earthquake).

6.1. Amphitheater Parking Structure (AM1)

The Amphitheater Parking Structure (AM1) has not been studied in the North Bayshore Precise Plan. It has been previously required to accommodate parking needs for the Charleston East project, but since that time the Alta/Huff Parking Structure has been built, and parking at the Google Landings project is under construction.

• Please consider removing the AM1 structure from the NBMPP or provide an alternative location(s) for parking in North Bayshore. As suggested above, putting a price on parking and a vehicle cap can go a long way towards reducing the need for parking. Such measures should be considered as an alternative to building this structure, especially at this scope and at this location.

Significant Impacts on Burrowing Owls
We are greatly concerned that the parking structure at AM1 will have a significant impact on Burrowing owls locally and regionally. A comment letter from the Department of Fish and Wildlife (April 6, 2022) also highlights the potential of impacts to Burrowing owls.

The Burrowing owl population in the south Bay Area has suffered a significant decline and the breeding population is at a risk of extirpation. In the past four years, the county’s Burrowing owl population has been sustained by deliberate conservation actions implemented primarily by the Santa Clara Valley Habitat Agency in an effort to accomplish the requirements of this adopted Valley Habitat Plan.⁸

The City of Mountain View has been engaged in conservation and monitoring efforts at Shoreline Park for decades and has been implementing a Burrowing Owl Conservation Plan since 1998. This plan was updated in 2012 with the adoption of the Burrowing Owl Preservation Plan⁹ (BOPP). The BOPP incorporated historical mitigation areas, stipulated Population and Habitat Goals, and designated additional areas (preserves) where owl habitat (for foraging and for breeding) is to be maintained to support wintering and nesting owls. The historical mitigations (Figure 1, from BOPP page 80) involve legal commitments to the California Department of Fish and Wildlife, and must be retained in perpetuity. Vista slope includes mitigation areas, including a mitigation site on the south-west corner of AM1. Vista slope has consistently been used by wintering and by nesting Burrowing owls over the years¹⁰ .

The City of Mountain View is an active participant in the Conservation Actions that are funded in part by the Habitat Agency. Shoreline Park has been one of only two locations where intervention actions by the Habitat Agency, including overwintering of fledglings and supplemental feeding, have been successful (Figure 2). Impacts to the success of Burrowing owls of Shoreline Park can potentially hamper recovery efforts in the south Bay Area and conflict with the adopted Santa Clara Valley Habitat Conservation Plan/ Natural Communities Conservation Plan.

Figure 1. Burrowing owl Mitigation Areas
 

FIGURE 2. Burrowing owl population trends at Shoreline Park¹¹ ,
showing the success and importance of recent intervention actions (2018-2021)

The BOPP (2012) provides:, “Under the California Endangered Species Act, the Burrowing owl is a State Species of Special Concern based on both localized and State-wide population declines as well as losses of suitable habitat (CDFG, 1995). Under California Fish and Game Code, Section 1802, the CDFG is the agency manager and trustee of fish and wildlife resources and their habitat.” The BOPP states, “this document also provides procedures for meeting wildlife laws and regulations without the City having to consult CDFG on every action taken at the Park that has the potential to harm Burrowing owls.” The Plan describes 10 Owl Management Actions, including “Action 9. Employ a full-time biologist with owl expertise.”

• Have the procedures for meeting wildlife laws and regulations been followed?
• Has the city’s Burrowing owl biologist been given the opportunity to participate in the design and mitigations of the parking structure at AM1? Has the biologist approved the proposed mitigations to ensure that procedures for meeting wildlife laws and regulations are met without the City having to consult CDFG?
• If the biologist has issued an opinion or a report pertaining to the design and mitigation of parking at AM1, please include these documents in the Final EIR for public and agency review.

To protect the Burrowing owls of Shoreline Park, the North Bayshore Precise Plan designated a buffer (Burrowing Owls Habitat Overlay Zone, HOZ) where buildings are not permitted within 250-ft of Burrowing owl habitat, and no net increase in impervious surface can occur. No buildings taller than 55 feet can be constructed within 100 feet of any HOZ boundary. There are additional stipulations regarding lighting, perching, pesticide use etc..

The 2017 NBPP EIR did not evaluate the construction of a parking garage outside of the Precise Plan area on Subarea AM1. The NBMPP proposes that the Parking Structure at AM1 will maintain the same 250-ft buffer that is required for development in the Precise Plan area, and comply with the measures listed in Chapter 5.1 Habitat Overlay Zone, Standard 2 of the Precise Plan regarding outdoor lighting, constructing perch deterrents, avoidance during construction, and the limitation of rodenticide use. We appreciate these measures, but maintain that these measures do not suffice to reduce impacts to a less than significant level.

As we understand it, the SDEIR makes two assumptions that lead to the findings that the impact is “Same Impact as Approved Project; Less than Significant Impact”:

1. Assumption 1: The edge of the potentially suitable Burrowing owl habitat is analogous to the baseline of the Burrowing Owl HOZ, and so mitigation can be similar.
2. Assumption 2: The developed/landscaped habitat in AM1 is of relatively low value to wildlife (including Burrowing owls).

We disagree with both assumptions.

There is a wide road (Amphitheater Parkway) that separates Burrowing owl habitat from the areas studied in the NBPP. It also provides, as we show below, Burrowing owl habitat. In contrast with the NBPP Study Area, AM1 is immediately adjacent to Vista slope and a designated mitigation site. The development and operations could therefore have impacts beyond those that were studied in 2017, including loss of habitat onsite, increased recreational activity on Vista Slope, hazards related to the anticipated increase in vehicle traffic, potential introduction of dogs and cats, and lighting in and around the structure. In the precarious situation of the owl population of the south bay, a loss of one nest, even one owl, during the nesting season can lead to the extirpation of the species in the South Bay Area.

Subarea AM1 is described in footnote 54 “The developed/landscaped habitat in AM1 is of relatively low value to wildlife, but provides nesting and foraging opportunities for some urban-adapted species of birds.” This description neglects to mention that Burrowing owls may also forage at the site. The footnote shows that the parking lot supports Burrowing owl prey species such as mice, lizards, and small birds. Burrowing owls are known to forage and even nest in parking lots. In “Studies of Western Birds 1:218– 226, 2008, Species Accounts (pages 218-226) (attached), the description of this California Species of Special Status includes, “developed environments pose a substantial risk to Burrowing owls from mortality caused by traffic (Klute et al. 2003, D. K. Rosenberg et al. unpubl. data). Owls nesting along roadsides or parking lots are at greatest risk, although owls foraged along roads over 1 km from the nest burrow (Gervais et al. 2003).” Burrowing owls have also been observed foraging in parking lots in North Bayshore7 .

The observation in the DSEIR footnote 54 that “California ground squirrels and their burrows are common in the ruderal grassland margins of the parcel, as well as on the adjacent grasslands at Shoreline Park” further substantiates the value of this site for burrowing owls. Overwintering or breeding Burrowing owls likely forage here, and potentially use ground squirrel burrows. The AM1 site is important to the preservation of Burrowing owls, and building here should be recognized as a significant impact and avoided, or adequately mitigated.

• Please discuss the impacts to Burrowing owls, including loss of habitat onsite, lighting, increased recreational activity on Vista slope, hazards related to the anticipated increase in vehicle traffic, potential introduction of dogs and cats, and construction-related activities.
• Please consider a regional context for the discussion of impacts to Burrowing owls and include:
  • Cumulative impacts on Burrowing owls. Please include the Moffett Park Specific Plan in Sunnyvale and development and maintenance activities in Moffett Park.
  • The role of Shoreline Park in the recovery efforts by the Santa Clara Valley Habitat Agency.

We believe that avoidance of the impacts by not building this structure is the best alternative. It was not part of the MPSP, and can be eliminated from the NBMPP. If avoidance is not feasible, the following mitigations should be added to the mitigations and standards offered in the DSEIR in order to reduce significant impacts to owls at Shoreline Park and regionally, and to the success of the Santa Clara Valley Habitat Plan.

• Plant grasses and shrubs in the 250-ft buffer to provide foraging for Burrowing owls.
• Ensure there is no-net-loss of impervious area/habitat.
• Install a green roof, seeded to provide grassy foraging habitat.
• Avoid any lighting or spillover light into the 250-ft HOZ. Lighting in the parking structure should not be visible from Vista slope.
• Fencing is needed to stop people from creating social trails to access Vista slope. Design and fencing should direct people to the official trails that provide signs and guidance (such as no dogs, day-use only).
• Additional Mitigation measures should craft best management guidance and requirements based upon the following:
  • Mountain View’s BOPP in consultation with the City’s Burrowing Owl Biologist,
  • CDFW Staff Report on Burrowing Owl Mitigation (2012) and consultation with the California Department of Fish and Game,
  • Mitigation measures for Burrowing Owls from the Santa Clara Valley Habitat Plan.¹²

7) Egret Rookery, Shorebirds Wilds and Eco -gem Area

The terminus of Charleston Rd./Shorebird Way is home to the largest egret and heron rookery in the South Bay. The rookery is recognized in the NBPP which states, “This rookery is regionally significant as one of the largest egret colonies in the South Bay and is an important natural resource.” In recent years, nesting birds in this area included Snowy Egrets, Great Egrets, Black-crowned night herons, White-tailed kites, Western bluebirds, Red-shouldered hawks and Red-tailed hawks (Matthew Dodder, SCVAS, personal Communications).

The use of 1201 Charleston for meeting/event space and outdoor activities in the Shorebirds Wilds and Eco-gem Area could introduce disturbance to nesting birds. The NBPP describes “passive” uses without defining what activities may or may not be permitted, or how these activities may accommodate nesting birds without disruption.

Mitigation measures to protect nesting birds from operations-related activities and disturbance should be specified for the lifetime of the project.

• Please develop Standards, Guidelines and Protocols to ensure that noisy or light-generating events, events that attract predators and/or other potential disturbances (especially outdoor activities) are evaluated by the City’s Biologist if they are scheduled to occur during the nesting season.
• In the letter from CDFW, the agency requests that the SEIR include building height and location alternatives that reduce environmental impacts such as not locating tall buildings near biologically sensitive areas. We ask that any facade that faces the egret rookery/Shorebirds wilds, the ecogem and the retention basin implement bird-safety measures (including glazing above 60-ft).
• Please develop a Tree Preservation Plan for the trees in the Egret rookery HOZ.
  • This plan should identify important trees to preserve. This should specifically include the London plane trees that are traditionally used by the egrets and the redwoods across Shorebird Way (including the redwood in which a White-tailed kite has been nesting).
  • The plan should specify maintenance requirements, importantly including irrigation with water with no salt content.

These mitigations aim to reduce the aesthetic impacts of loss of trees and canopy, and the risk that the London Plane trees die due to over-fertilization and high salt content by recycled water augmenting the bird excrement, or that the redwood trees die due to high salt content in recycled water). Both of these outcomes are known to occur if these trees are irrigated with high salt content water. If protective measures are not taken to ensure that the trees thrive, the trees of the egret colony may perish - a potentially significant impact to the largest heron/egret rookery in the South Bay area.

8) Potential Loss of Trees

The loss of trees and canopy, and mitigations for such loss, are of great public interest in Mountain View. In 2022, the City has prioritized Biodiversity as a strategic goal, and within this goal, a new Urban Forest Master Plan is being developed. The new Plan, with associated code changes, is likely to be completed within two years and change the existing, inadequate regulations for the protection of trees.

COA BIO-2.1, “Tree Mitigation and Preservation Plan” defers the preparation of a Tree Mitigation Plan and at the same time grandfathers in existing tree mitigation requirements for decades to come. However, in light of the ecological sensitivity of North Bayshore, note the following.

• It is important that future projects implement the new policies and ordinances that are developed to protect biodiversity and the environment, including requirements for mitigation for the loss of trees. The existing code regarding trees should not be static and grandfathered in. An update to the NBMPP should be required when the tree ordinance is updated.
• Identification of locations where replacement trees will be planted (so the city does not end up with in-lieu funds but no viable planting locations) is important, including potential planting locations outside the boundary of North Bayshore.
• Please identify redwood trees/groves to preserve similar to Landings projects.
• In addition, please see our previous comment regarding the development of a Tree Preservation Plan for the trees in the Egret rookery HOZ (Section 7). This plan should be incorporated into the Tree Mitigation and Preservation Plan and include directions for maintenance and preservation of the London Plane and redwood trees that comprise the rookery so the trees are retained and maintained in good health. Trimming guidelines are also needed, and a plan to continue supplying water of low-salt content. This is because irrigation of redwoods in North Bayshore with recycled water of high salt content has led to a rapid decline in the health of the trees. London Plane trees are more resistant to salinity, but fertilization by egret droppings augmented by irrigation with water of high salinity may impact the health of these trees adversely.

9) Cumulative Impacts Analysis

Why has the cumulative Impact analysis not addressed Google’s Bayview Campus, Caribbean campus and the City of Sunnyvale’s Moffett Park Specific Plan? These projects are located in close proximity to the NBMPP (a biking/walking distance) along the Bay. These projects and plans introduce millions of square feet of office space and thousands of hotel rooms and housing units. The implementation of the Moffett Park Specific Plan is expected to coincide with the development of the NBMPP. All these projects have a Google nexus, and all may have cumulative impacts on Biological Resources, air quality, traffic and other environmental resources. We encourage the City to analyze the cumulative impacts of these additional projects.

10) Artificial Light at Night

In the time since the NBPP was adopted, scientific evidence and understanding of the devastating impacts of Artificial Light At Night (ALAN), especially in the blue band of the spectrum, has grown substantially. We now know much more about impacts of ALAN to the environment and to human health, and we have a better understanding of how to mitigate the impacts¹³. The Artificial Light at Night Research Literature Database includes many recent (2018-2023) scientific studies¹⁴ that focus on the harmful impacts of LED lighting to species, ecosystems and human health, impacts that were not known, and could not have been discovered, when the NBPP was approved in 2017. The primary lesson that emerges from these studies is that ALAN must be minimized.

This upcoming update to City code, and the proliferation of new scientific evidence, justifies a reevaluation of the NBPP standards and strengthening the existing requirements by the following.

• Eliminating minimum requirements for lighting from the NBPP and the NBMPP. Lighting for all human needs can be achieved without setting minimums.
• Turning off all outdoor lights at 10PM.
• Ensuring that Correlated Color Temperature should not exceed 2700 Kelvin (with potential exception to vibrant social activity centers).
• Including as Standards and Guidelines the best practices that the International Dark-sky Association (IDA) provides in its Board Policy on the Application of the Lighting Principles document¹⁵ (June 24, 2021). This policy provides guidance for implementing the Five Principles for Responsible Outdoor Lighting¹⁶ that are offered as mitigation for the significant impacts of ALAN on the environment. These guidelines include the following among other recommendations.
  • The spectral content, or color, of light should be limited to only what is necessary for the task. Because of the disproportionate impact on the nighttime environment, particular attention should be paid to reducing the total emissions of short-wavelength or “blue” light (defined for the purposes of this resolution between the wavelengths of 380 nm and 520 nm) through light source spectrum management¹⁷ .
  • To minimize negative environmental impacts, IDA recommends using lamps rated at 2200K CCT¹⁸ , Phosphor-Converted Amber LED, or some filtered LED.
  • When higher than 2200K CCT is necessary to meet lighting objectives, keep the total emission of blue light into the environment as low as reasonably possible through low intensities, careful targeting, and reduced operating times.
  • Near sensitive sites, such as conservation areas, sensitive wildlife habitat, ecological reserves, parks, astronomical observatories, or stargazing sites, IDA recommends that lighting installations use 0% blue light and a narrower spectrum of emission.
  • Critically sensitive environments should be kept naturally dark.
• Tall buildings that emit internal light at night can divert bird migration patterns and increase bird collisions.¹⁹ Any buildings that face ecologically sensitive areas should include window coverings that can be drawn at night to reduce visibility of light from surrounding areas. We are especially concerned with the lighting of parking garages, particularly the proposed garage on Amphitheater Parkway.

11) Hydrology

Have impacts of the Project to the hydrology of the Charleston Retention Basin been analyzed? Please ensure that the wetland is not deprived of water.

We thank you for the opportunity to provide comments,

Susan DesJardin
Bay Alive Committee Chair
Sierra Club Loma Prieta Chapter

Matthew Dodder
Executive Director
Santa Clara Valley Audubon Society

Alice Kaufman
Policy and Advocacy Director
Green Foothills

¹ North Bayshore Precise Plan https://www.mountainview.gov/civicax/filebank/blobdload.aspx?BlobID=29702

² https://www.aplic.org/Collisions.php. For guidance, download APLIC’s “Reducing Avian Collisions with Power Lines: State of the Art in 2012.”

³ https://www.aplic.org/APPs

⁴ http://www.aqmd.gov/docs/default-source/transportation/supplemental-documents/ca_parking_cashout_program_an_informational_guide_for_employers_2021.pdf?sfvrsn=6

⁵ https://www.greenbiz.com/article/how-genentech-used-parking-lot-fund-its-employee-commuter-shuttle

⁶ https://transportation.stanford.edu/about/stanford-and-general-use-permit-faq

⁷ https://mtc.ca.gov/planning/transportation/driving-congestion-environment/parking-curb-management

⁸ https://scv-habitatagency.org/DocumentCenter/View/1691/06

⁹ http://www.elkhornsloughctp.org/uploads/files/1408724962Mountain%20View%20Burrowing%20owl%20manag ement%20plan.pdf

¹⁰ Shoreline Burrowing owls Annual Monitoring reports, 1998-2021.

¹¹ https://scv-habitatagency.org/DocumentCenter/View/1691/06

¹² https://www.scv-habitatagency.org/178/Santa-Clara-Valley-Habitat-Plan

¹³ https://www.darksky.org/artificial-light-at-night-state-of-the-science-2022-report/; Artificial Light at Night: State of the Science 2022 International Dark-Sky Association DOI: 10.5281/zenodo.6903500 (attached)

¹⁴ https://www.zotero.org/groups/2913367/alan_db

¹⁵ https://www.darksky.org/wp-content/uploads/bsk-pdf-manager/2021/08/BOARD-policy-application-of-lightFINAL-June-24-2021.docx.pdf

¹⁶ https://www.darksky.org/our-work/lighting/lighting-principles/

¹⁷ Outdoor light emission in the ultraviolet portion of the spectrum (below 380 nm) should also be avoided as it often has deleterious consequences for wildlife while providing no benefit or human utility. https://www.darksky.org/our-work/lighting/values-centered-outdoor-lighting/

¹⁸ There is no widespread agreement on a more relevant metric than CCT for spectrum evaluation until one is developed. In the interim, CCT may be used as a placeholder, although it should be verified that the source emits no more than 8% blue light emissions

¹⁹ https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1002/fee.2029?af=R and https://www.pnas.org/doi/full/10.1073/pnas.2101666118