Staff Report-Sterling Park Street Light Replacement Project, Study Session 1-08-2025
STAFF REPORT
TO: Mayor and Members of the City Council
FROM: Brad Donohue, Director of Public Works
VIA: Dan Barros, City Manager
MEETING DATE: January 08, 2025
SUBJECT: Sterling Park Street Lights
RECOMMENDATION
This item is a study session for information purposes only. No City Council action is required; however, staff seek comments, questions, impressions and opinions from Council members and members of the public regarding streetlight options for the Sterling Park Residential Neighborhood.
COUNCIL ADOPTED VALUES
The recommendation is consistent with the Council value of responsibility by taking a proactive approach in the replacement of deteriorating streetlights before they become a hazard to the residents and property in the Sterling Park Neighborhood.
BACKGROUND
In April of 2020, the City Council held a study session to review and give direction to staff regarding the condition and replacement options for the deteriorating ornate streetlights in the Sterling Park Residential Neighborhood. A Streetlight Replacement report (Attachment A) was presented and reviewed. The report analyzed the current condition of the 100 ornamental streetlights. The report documented that numerous light standards were showing signs of deterioration, sometimes significant, most notably amounts of rust bleeding through the exterior paint on the steel streetlight poles. Each streetlight within the neighborhood was inspected by the Public Works supervisor (L. Gotelli) and a CSG Principal Engineer (E. Slintak). The inspection report assigned a numerical condition rating of 1 to 3, with 3 representing the most severe deterioration (attachment “B”). The rating is based on visual observations of the streetlight and the extent of visible corrosion on the pole’s exterior.
The April 2020 study session also reviewed viable options regarding streetlight pole replacement.
City Council reviewed:
Staff Report-Sterling Park Street Light Replacement Project, Study Session 1-08-2025
Streetlight Material
The proposed streetlight pole options come in a variation of materials, aluminum, steel, composite materials (fiberglass and resin) and concrete. The City Council’s preference was to go with the concrete pole assembly.
Streetlight Characteristics
City Council’s direction was to make sure that the replacement pole meets the same ornate standard that is currently in the neighborhood. The replacement streetlight pole assembly needs to be fluted pole with a single luminaire (acorn LED lighting unit). The pole would also be equipped with a GFI receptacle for holiday displays. City Council also stated their preference was to keep the green color, match as close to possible the green that is existing on the current poles. Directions was also given that the new replacement pole needs to be compatible with the existing streetlight foundation and the bolt fastening feature that is already part of the existing streetlight foundation.
Streetlight Costs
The range of costs for the above-mentioned types of streetlight poles range from $ 6469 aluminum pole to $6,668 for the concrete pole assembly. It was also noted that all prices are as of early 2020 and will likely increase annually.
In summary, City Council gave directions to staff to pursue the concrete streetlight pole option and erect two streetlight assemblies so that they can be viewed by the City Council and residents, to make their preferred choice. Because the order would be substantial, staff wanted to display two different Street Light assemblies to get both City Council and resident buyoff on what concrete pole assembly was desirable and that the concrete streetlight pole assembly would meet the characteristic that came from the previous study session.
ANALYSIS
The Sterling Park Street Light Replacement Project was initially put on hold due to the COVID Pandemic. Once the pandemic was lifted other capital projects moved in front of the Sterling Park Replacement Project. In 2023 staff resurrected the project. Once staff moved to reestablishing the order to get our sample products, we were confronted with several obstacles, some minor and major.
The most severe item was the hole at the base of the concrete pole. The hole at the base of the pole is where the electrical components, (Conduits and electrical wiring) enter the streetlight pole. The existing streetlight pole has a 10-inch access hole, that gives amble access for the conduits, wiring and grounding to fit comfortably. The proposed concrete pole has only a 4-inch hole and if the conduits are not centered in the middle of the streetlight foundation, modifications to both foundation and streetlight pole would be required. We were also told that modifications to the pole may void any warranty. The costs for such work could range from hundreds to a few thousand on each pole. (Major Issue)
Staff Report-Sterling Park Street Light Replacement Project, Study Session 1-08-2025
The other major issue was the cost per pole, in 2020 the estimated cost per pole was in the range of $ 6,668. Currently we have received an updated cost estimate and the cost per pole increased to $11,159, a 60% increase. (Major Issue)
A minor issue but somewhat discouraging was the unmerited delays in getting the sample poles. When the order was placed with the manufacturer, via the electrical warehouse vendor, they were told the lead time would be in the range of 16 weeks, maybe a little longer given that the order was small, and a special setup would be required. The order took approximately 14 to 16 months, and the order arrived in pieces. (Minor Issue)
If delivery was the only issue, staff felt that we could work this out but given the fact that modifications to the pole and foundation would need to take place and the cost of the pole assembly increased substantially, we are recommending that City Council reconsider moving from concrete to a metal pole.
Staff requested from the vendor who has supplied streetlight assemblies for Hillside Boulevard, Mission Road and Junipero Serra Boulevard. The pole assembly would match in style the poles that are currently being used in the abovementioned streets. The recommended pole would match the style of the other poles, the difference would be the color, pine green in lieu of black and the pole would be equipped with an electrical receptacle for holiday displays. Staff received an estimate, the cost of a single streetlight assembly is $ 5,050, is less than half the cost of the concrete pole assembly.
Other nonmetal pole assemblies can be considered, such as fiberglass composites. Staff feels this is not a viable option right of way streetlighting. With the composite material, it is unclear if the color would fade over time and how would you restore the color if needed. The other concern is the electrical outlet, it is also unclear if the pole can accept the electrical receptacle box without damaging the integrity of the pole. Staff has not received a current estimate, but it is believed that the cost of the composite pole is in the same range as the aluminum pole.
Cost Sharing
Staff will be working with the Colma Lighting District (Managed by the San Mateo County Public Works Department) by either annexing Colma’s portion of the Lighting District and using the current reserve fund balance that could substantially offset the cost of replacing the residential streetlights
Phase II of the Sterling Park Residential Street Light Replacement Project:
The next phase of this project will provide a specific review of the Council preferred streetlight option, detailed cost estimates, plans and specifications, and a feedback on potential funding from the Colma Lightning District.
FISCAL IMPACT
None at this time.
Staff Report-Sterling Park Street Light Replacement Project, Study Session 1-08-2025
Though there is no fiscal impact in reviewing and discussing the streetlight options for the Sterling Park Residential Neighborhood. There are future costs associated with project plans and specifications along with construction/installation costs. These items will be addressed in Phase II of the Sterling Park Residential Street Light Replacement Project.
ENVIRONMENTAL
Staff finds that the replacement of streetlights is exempt from environmental review under the California Environmental Quality Act (CEQA) pursuant to both CEQA Guideline 15301 and 15302 both on a separate and independent basis. CEQA Guideline 15301 is applicable because this would be considered the repair, maintenance, and minor alteration of an existing public facility/utility with no expansion of use. Further, CEQA Guideline 15302 is applicable because this would also amount to replacement of existing public facilities on the same site and with the same purpose and capacity as the structure replaced.
CONCLUSION
The City Council and members of the public are encouraged to ask questions about proposed streetlighting options for the Sterling Park Neighborhood and move this project to the next phase if City Council directs staff.
ATTACHMENTS
A. Sterling Park Streetlight Report
B. Vendor estimates on concrete and aluminum streetlights
Attachment “A”
Town of Colma
Sterling Park Neighborhood
Residential Street Light
Evaluation Report
Prepared By: CSG Consultants
April 2020
This Page Intentionally Blank
ii
Table of Contents
Introduction ………………………………………………………… 1
Background ……………………………………………………….. 1
Inspection …………………………………………………………. 2
Alternatives ………………………………………………………... 4
Corrosion ……………………………………………………... 4
Aesthetics …………………………………………………….. 5
Ease of Construction ………………………………………… 5
Maintenance ………………………………………………….. 6
Visual Compatibility
……………………………………………
6 Cost
……………………………………………………………..
7 Recommendations ………………………………………………… 8
Figures and Exhibits
Exhibit A – Aerial view of Sterling Park Neighborhood
Exhibits B-1 & B-2 – Streetlight map with inspection ratings Exhibit C – Photos showing damage
iii
This Page Intentionally Blank
1 Introduction
The purpose of this study is to review the current condition of 100 ornamental streetlights located in the Sterling Park Neighborhood, a residential area of Colma.
Public Works staff had observed that numerous light standards were showing signs of deterioration, sometimes significant, most notably rust on the steel poles. Each streetlight was inspected by the Public Works supervisor (L. Gotelli) and a CSG Principal Engineer (E. Slintak), and assigned a numerical condition rating of 1 to 3, with 3 representing the most severe deterioration. The rating is based on visual observations of the streetlight and the extent of visible corrosion on the pole’s exterior.
Only the extent of the visible corrosion was observed, and no in-depth forensic analysis was performed as to the cause of the deterioration. Replacement alternatives were reviewed and are discussed later in the report. Estimates of replacement costs for various alternatives were developed.
Background
The Town undertook a significant renovation of the residential area in approximately 1998. The Colma residential area, referred to as the Sterling Park Neighborhood, is a compact area generally defined as bordered on the north by the Daly City / Colma City Limit (located between A and B Streets) to the south by the Italian Cemetery (F Street), on the east by Hillside Boulevard and by El Camino Real to the west. See Exhibit A.
The renovation included undergrounding of overhead utility lines, reconstructing the streets and sidewalks with paving stones, and installing new ornamental streetlights.
The streetlights, which are the subject of this report, include a dark green fluted steel pole approximately 16 feet tall to the bottom of the top piece, a decorative cast iron base, and a top piece that supports two acorn-style lights. Anecdotal reports at the time of installation indicated that residents were concerned the new lighting level was “too bright” and that the double lights on each pole may have been “too much”.
Subsequent residential developments, such as the condominiums located on Mission Road near Lawndale, adopted a similar streetlight concept consisting of a fluted pole, decorative base, and a single acorn-style light fixture. Subsequent beautification projects on Junipero Serra Boulevard (2004/2005) and Hillside Boulevard (2014) continued the concept of the Mission Road lighting style utilizing an all-aluminum pole assembly manufactured by Holophane. While originally installed with incandescent light sources, all have been retrofitted with LED technology.
While the Town paid for the construction and installation of the various beautification projects the streetlights are owned and operated by the Colma Lighting District, administered by San Mateo County.
2 Inspection
The streetlights were visually inspected on 27 December 2019 by Louis Gotelli, Public Works Supervisor, and Ed Slintak, P.E., CSG Principal Engineer. Each streetlight was inspected and given a condition rating number based on a scale of 1-3, with 1 representing good condition and 3 representing poor condition. The scale is further explained below.
Colma Streetlight Rating scale
1.0 Good condition: No rust visible or only small patches, generally at corners or sharp edges.
1.5 Fair condition: Larger rust areas visible, beginning of bubbling* of surface.
2.0 Marginal condition: Significant rust patches, rust “bubbling” under the exterior coating, significant additional deterioration likely.
2.5 Deteriorated Condition: Larger rust patches, beginning of “blooming #” of
surface finish, oxidized metal can be flaked off when gouged with a key or screwdriver.
3.0 Poor condition: Large rust areas, surface finish “blooming#” from underlying oxidation, oxidized metal can be flaked off when gouged with a key or screwdriver, in some instances holes through the steel shell are observed. Or other significant defects, such as cracked base.
*Bubbling indicates that the surface finish is mostly intact but with bubbles showing on the surface. # Blooming indicates that the surface finish is missing or is broken and peeling back from the substrate material.
Inspection results for all 100 streetlights in the residential area are summarized below and are displayed on Exhibits B-1 and B-2.
Condition
Assessment
Score
Description Number of
Streetlights
1.0 Good 32
1.5 Fair 26
2.0 Marginal 18
2.5 Deteriorated 7
3.0 Poor 17
TOTAL 100
3 Exhibit A - Sterling Park Neighborhood, Colma
4 It is the opinion of Colma Public Works staff and the author that while this inspection is based on the visible condition of the pole exterior as observed from ground level, the level of corrosion in the upper reaches of the pole and especially on the interior surfaces is an unknown and may potentially be more significant than what is observed on the exterior surface.
Excessive corrosion may pose stability concerns if unusual circumstances occur, such as being struck by a vehicle, seismic shaking, or unusually high winds. To a lesser extent, excessive corrosion also poses aesthetic concerns for residents and visitors.
Alternatives
Repair of the existing lights is not deemed a feasible option because of the deep intrusion of the corrosion in many units and the unknown condition of the interior spaces.
Replacement street lights are constructed of a variety of materials, including:
• Steel
• Aluminum
• Composite Materials or Resin
• Concrete
Factors influencing selection of streetlights include:
• Longevity (corrosion resistance)
• Aesthetics
• Ease of Construction
• Maintenance
• Visual consistency with other units in Town
• Cost
The influencing factors are described in more detail below.
Corrosion
Steel - Steel products are susceptible to oxidation (rust). Exterior coatings have evolved beyond traditional painting techniques, such as fusion bond epoxy powder coating (powder coating).
Powder coating can be very effective provided the surface is cleaned and prepared properly before application. Any breaks in the surface coating potentially exposes the underlying steel to moisture.
Aluminum - Aluminum poles are available and are also subject to corrosion, however, aluminum oxidation is not rust but forms an aluminum oxide compound which forms a protective layer on the surface of bare aluminum. For the Town’s purposes, continuing the
previous practice of application of a powder coating to the pole exterior for the added protection and aesthetic purposes would be recommended
Aluminum pole section.
5 Composite - Composite materials generally consist of a central core of a steel pipe for rigidity, an extruded foam layer that provides the exterior shape of the pole (such as flutes) that is covered with a plasticized resin material for color and finish details. The steel core may be made of stainless steel for corrosion resistance. The resin material is generally impregnated with the color throughout the thickness of the resin material. The manufacturers claim that the resin material is UV resistant. To our knowledge, there are no resin poles in service in the immediate area to observe how the resin surface weathers over time.
Concrete – Concrete poles are generally manufactured utilizing one of two processes, one process consists of placing the concrete material into a form and using a combination of mechanical tamping and vibration to ensure the concrete fills all the spaces in the form and consolidates (compacts) the concrete to a dense mass. The other method consists of introducing the concrete into the form and then consolidating the concrete by centrifugal force, spinning the filled form around the axis to fill all spaces and consolidate the concrete.
Concrete poles have been observed in use for many years in San Francisco and certain South Bay cities. Concrete light poles have recently been installed in certain City of Alameda parks and in the Crestmoor neighborhood in San Bruno (site of the PG&E gas explosion).
The concrete material is not prone to corrosion, however if the surface is chipped due to accident or other physical impact, the underlying steel reinforcement can be exposed and may be prone to rusting.
Globes - Another factor related to longevity is the material that the “glass” globe of the light fixture is manufactured from. Actual glass globes (usually borosilicate glass), while heavier and more expensive, are not prone to the yellowing that globes manufactured of polycarbonate materials tend to develop with age. The yellowing of the glass lens decreases the light output available on the street.
Summary – Steel poles retain the potential for rusting if the surface finish fails to continuously protect. Aluminum and resin poles are considered non-rusting. Concrete poles do not rust unless moisture gets to the underlying steel reinforcement.
Acrylic globes tend to discolor or yellow over time, glass globes retain their clarity.
Aesthetics
Aesthetic considerations are highly subjective. For purposes of this report, it is assumed that the Town would desire to maintain a certain level of consistency.
Elements of the current streetlights in other areas of Town would include:
• Fluted pole
• Decorative base
• Acorn style luminaire with ribs and cap.
• Dark Green color
6 Fluted poles (either straight or tapered) seem to be available in all materials. Decorative bases are widely available, but do vary in style in the different materials and by
manufacturer.
Metal poles have a smooth exterior finish, composite / resin poles have a slight grainy texture, whereas the concrete pole has a rougher surface finish.
Concrete poles can be ordered in various colors, including green, however the color only affects the cement and the natural color of the aggregate (gravel) is still visible. It is unlikely the dark green color of the other poles in Town could be applied to the concrete surface.
The acorn style luminaire is a common and classic style of globe. Most manufacturers offer some form of acorn globe, but not all offer ones with the ribs and metal cap.
Ease of Construction
The simplest methodology to replace the streetlights would be to install the replacement unit on the existing foundation. The current lights are constructed on a 24” diameter, 5’ deep concrete foundation. This method would not involve any modification to the existing sidewalk paving or the electrical wiring already in place. Based on load data received from one manufacturer, the existing foundations were assessed for their ability to support the forces imparted (dead load, wind load, and seismic forces) and the existing foundations provide adequate support.
Many concrete light poles are designed as direct burial installations. The pole continues several feet below ground level. Installation consists of drilling a hole and setting the pole in place. This would require removing the existing foundation and some of the sidewalk pavers and modifying the electrical conduit feeding the electrolier. Concrete poles are also heavier than the other materials and would require equipment with a greater lifting capacity than the other options
Most of the composite material poles are also designed as direct-burial installations, but several are available configured to bolt down on an existing foundation.
The steel and aluminum poles, when ordered with a compatible mounting bolt pattern, should be able to be bolted directly in place. If any of the existing bolts are found to be corroded or otherwise damaged, new anchor bolts can be drilled and epoxied into place in the existing foundation.
Composite pole section with grainy
surface finish.
7 At the corner of F Street and Clark Avenue one of the spare single- head streetlights from the Hillside Avenue project was used to replace an existing unit and it bolted onto the existing foundation.
Maintenance
Metal poles will most likely come with a powder coat finish, which is very durable and has good longevity when applied correctly. If damaged, it can expose the underlying metal. Touch ups with paint can correct the damaged sections. In some cases, it may be desired to paint major sections of the pole for visual continuity.
Composite poles with a resin exterior have the color impregnated throughout the resin material so that even cuts or gouges should not expose an underlying different color.
Concrete poles should require no periodic maintenance to maintain their concrete surface, however if a concrete pole sustains physical damage and chips the concrete surface repairs could be difficult and would likely be very visible as a repaired surface.
Other maintenance considerations include limiting the number and diversity of spare parts needed to be maintained by Public Work staff to maintain the streetlights in good working order.
Visual Compatibility
Maintaining a consistent style for all the Colma decorative streetlights is highly desirable. This is limited to those pedestrian scale lights with the acorn style fixture as used in the residential areas and the Hillside and Junipero Serra Boulevard beautification projects and does not include the Caltrans style streetlight such as installed in the median of Junipero Serra Boulevard or on other public streets.
The major visual elements include a fluted pole cross section, either straight or tapered, a decorative base approximately 24” tall, and an acorn shaped light fixture with metal ribs and cap. The ribs are the four pairs of metal rod that connect the base of the fixture to the metal cap piece.
Cost
The cost for replacement of existing streetlights consists of two major components, the purchase price and the labor cost for installation. There may be some salvage value associated with the removal of the existing lights.
For purposes of this evaluation an installation cost of $2,500 per unit was assumed, except for concrete units where the extra weight may require larger lifting equipment, for concrete an installation cost of $2,700 per unit was assumed, exclusive of material costs. For budgeting purposes, a quantity of 25 units was assumed. In addition to being ¼ of the total, this is the number of units rated with an assessment score of 2.5 or 3.
F Street and Clark
Avenue
8 Aluminum - A price quote from Holophane, the suppliers of the JSB and Hillside streetlights, was received and is summarized below.
- 16’ fluted aluminum pole with decorative base, GFI receptacle, LED light unit, and decorative borosilicate glass acorn fixture:
$3,650 each
- Sales tax (8.75%) $ 319
- Total each $3,969
- Installation $2,500
- Installed cost $6,469
Total cost for 25 units - $161,725
Substituting the acrylic globe for the glass unit would reduce the cost approximately $330 per unit.
The total cost per unit consists of the pole at $2,000 and the luminaire (lighting unit) at $1,650.
Another supplier, Sentry was contacted for pricing information. They provided pricing for luminaires and poles and their pricing was very similar to Holophane.
Steel - Holophane and others also supply steel poles with cast iron decorative bases. A similar installation using steel poles instead of aluminum would result in an increase in price of approximately $1,000 - $1,200 per unit.
Concrete – A price quote from Stress Crete, manufacturers of centrifugally spun concrete poles (suppliers of the concrete poles used in Crestmoor area of San Bruno) was received and is summarized below.
- 16’ fluted concrete pole with decorative base & GFI receptacle: $2,000 - LED light unit, and decorative borosilicate glass acorn fixture: $1,649 - Sales tax (8.75%) $ 319
- Total each $3,968
- Installation $2,700
- Installed cost $6,668
Total cost for 25 units - $166,700
Composite / Resin – An estimate for a composite /resin pole unit was quoted at approximately $1,600. Adding a similar cost for the lighting unit of $1,650 creates a total cost for materials of $3,250
- 16’ Composite pole with decorative resin base and LED light unit: $3,250 each - Sales Tax (8.75%) $ 284
- Total each $3,534
- Installation $2,500
- Installed Cost $6,034
Total cost for 25 units - $150,850
Existing unit on F
Street
9 COST SUMMARY
The following summarizes the cost per unit and the projected total cost for 25 units:
Unit Cost 25 Units
Aluminum $6,469 $161,725
Composite/Resin $6,034 $150,850
Concrete $6,668 $166,700
Note that all prices are as of early 2020 and all costs will likely increase on an annual basis.
Recommendations
Two-thirds of all the existing streetlights in the Sterling Park area are exhibiting some level of visible corrosion. Of those, 24 have been rated as Deteriorated or Poor condition. To receive those ratings significant areas of the surface are showing rust, the exterior protective coating is cracked or missing at these locations and further corrosion is only a function of time.
Another 44 units are also showing signs of rust albeit to a lesser degree. However, it would be logical to assume that the corrosion will continue and advance over time.
Patches of visible rusting is certainly unsightly and degrades the “look” of the surrounding area. Deeper seated corrosion raises concerns about when it might affect the structural integrity of the pole. Streetlight stability is at its most critical during impact (such as being struck by a vehicle or equipment), seismic shaking, or unusually high winds.
An attempt at repair of the less severely corroded units could be made to prolong their useful life but its ultimate success is dependent on how thoroughly the repair operation could chase the visible corrosion into recesses and cracks. While it could extend the useful life it is highly probable that the corrosion would reappear in the current locations and may also show itself in new locations.
Replacement using more durable construction materials, while expensive, would provide a less maintenance intensive installation and provide a clean look. Replacement would eliminate any concerns about the structural integrity of the streetlight being compromised by the visible corrosion.
Our recommendation would be to institute a program to replace the severely corroded units in the most expeditious manner possible. We would further recommend that the units displaying less severe corrosion should also be replaced as soon as time and budget allows, as their further deterioration is almost certain with the passage of time.
The recommendation for the type of streetlight construction to use as a replacement would be for an aluminum pole and decorative base unit with a single luminaire (globe).
These are available from several manufacturers in styles that include the fluted pole and
10 acorn style light with the decorative elements that would be compatible with the other decorative fixtures in use in the Town. This type of unit would provide a relatively simple replacement, being able to be secured to the existing streetlight foundations.
Direct burial concrete units are not recommended due to the need to remove the existing foundation and drill a new foundation hole for placement of the light standard.
Some manufacturers do offer units that could be bolted to the existing foundations. The bolt down units would be an option to consider. The price is very similar to the aluminum units and the surface texture, finish, and color would be different than the existing units currently in use in various parts of town.
The composite construction / resin units are not recommended because they appear to be relatively new technology without a long-term performance record. The preferred method of installation is direct burial, similar to concrete units but they are available with a bolt-down option which may be compatible with the existing foundation. They seem to be in use primarily in the southeast US and do not have a discernable west coast presence with which to evaluate their look and performance.
Steel units would be susceptible to corrosion and they have a purchase price approximately $1,000 higher than comparable aluminum units.
It is our opinion that strong consideration should be given to using the aluminum units distributed by Holophane as the replacement standard, for the following reasons:
• In use on Hillside and JSB, providing good service
• Would be visually compatible with existing units
• Has already been used as a bolt-on replacement (Clark and F St.) • Maintenance familiarity
• Common design requires a smaller spare parts inventory
EXHIBIT B
11 EXHIBIT B
12 EXHIBIT C
13 Sterling Park Neighborhood Streetlights, Town of Colma Condition Assessment Score = 3
EXHIBIT C
14 Sterling Park Neighborhood Streetlights, Town of Colma Condition Assessment Score = 1.5 - 2.5
5 Score = 2.0
2.0 Score = 1.5
EXHIBIT C
15 Sterling Park Neighborhood Streetlights, Town of Colma Condition Assessment Score = 1.5
Score = 1.5 Score = 1.5
Single-head streetlights along Hillside Boulevard