CAVE-219342-Final CD Pkg_PKA Coatings Letter Report_0001.pdf

pKa Paul Kofoed Associates, Inc.

800 Castleton Court

Mundelein, Illinois 60060

847.863.2720 cell www.pkofoed.com

Via Email: Jon.Holbrook@hdrinc.com

February 13, 2020

Mr. Jon H. Holbrook, AIA, LEED AP Associate Vice President, Senior Project Manager, HDR, Inc.

1670 Broadway, Suite 3400 Denver, Colorado 80202

Re: PKA Coatings Letter Report for Remedial Coatings Specification Carlsbad Caverns Elev. 1&2 Replacement PD/SD PMIS 219342 PKA No. 2019030

Dear Mr. Holbrook:

Please find herein a coatings letter report that details: (a) Paul Kofoed Associates, Inc. (PKA) laboratory studies of additional Carlsbad Caverns National Park, New Mexico, water specimens procured by and received from JVA, Inc. and (b) coating specifications prepared by PKA for suitable remedial coating system(s) for existing carbon-steel structural beams at the top and bottom regions of Elev. 1&2 shaft, specifically Carlsbad Elev. 1&2 Replacement PD/SD PMIS 219342 project. These services are in addition to previous work and consultation PKA has provided regarding: (a) limited remedial touch-up coating consultation in 2016 for the previous Elev. 1&2 project and (b) Carlsbad Caverns water-chemistry analyses and associated stainless-steel grade consultation in 2019 for the Elev. 1&2 project.

The laboratory and coating specification design efforts performed by PKA include the following.

1. Laboratory studies of additional Carlsbad Caverns Elev. 1&2 shaft water specimens procured by and received from JVA, including (in part) measurements and determinations of pH, chloride ion, total dissolved solids (TDS), and conductivity.

2. Research of technical literature of previous chemical analyses of Carlsbad Caverns cave water sampling.

3. Review of documentation of on-site environmental conditions of Elev. 1&2 shaft, including temperature and relative humidity.

4. Evaluate existing conditions of installed coating system(s) and underlying carbon-steel substrate(s), as technical information and documentation made available for our review, as well as detailed technical discussions with JVA engineering personnel.

5. Review of previous coating specifications pertaining to Elev. 3&4 shaft project.

6. Review of pertinent coating manufacturers’ technical literature.

7. Research of coating and steel technical literature as pertains to durability properties and characteristics when exposed to its intended service environment at Carlsbad Caverns National Part, Elev. 1&2 shaft project.

8. Review of pertinent National Park Service (NPS) Carlsbad Caverns documents and discussions, including their Lessons Learned document specifically pertaining to the Elev. 3&4 shaft coatings repair project of structural and elevator transport assemblies steel members and components.

Mundelein, Illinois 60060

Laboratory Studies

Various water-sample chemical-constituents and physical properties were assessed by laboratory studies on four additional water specimens reportedly procured and submitted to PKA by JVA, Inc. personnel. A summary of the resultant values is provided in Table 1. Designated identifications and locations for Water Samples A’ through D’ are listed in Table 1.

Solution pH, temperature, conductivity, and TDS values were obtained using a Hach Pocket Pro+ Multi 2 electronic tester unit. pH values ranged from 7.8 to 8.2, which considered to be slightly alkaline. The samples had been allowed to acclimate to room temperature conditions prior to measurements. Conductivity values ranged from about 462 to 510 µS/cm for all tests, except Water Specimen D’, which had a solution conductivity value of about 1099 µS/cm. Similarly, TDS values ranged from about 328 to 364 ppm in all tests, except for Water Sample D’, which had a value of about 779 ppm.

Chloride ion concentrations were measured using Hach Quantab (Low Range) titrator strips. The chloride concentration was below the detection threshold of 30 ppm in all tests except that for Specimen D’, which had a value of 87 ppm. Some slight sediment particulates were visually evident with Water Specimen D’.

Chloride concentrations less then 100 ppm are normal in freshwater.

Sulfate ion concentrations were measured using a Hach Sulfate Test Kit (50 to 200 ppm Range), Model SF1. Values ranged from less than 10 to 70 ppm sulfate ion in all tests, except for that of Specimen D’, which had a value of greater than 200 ppm.

Nitrate and Nitrite ion concentrations were measured using Hach AquaChek test strips. Nitrate concentrations ranged from 1 to 15 ppm. Nitrite concentrations were essentially zero (below the detection limit).

Manganese ion concentrations were measured using a Hach Manganese Test Kit, 0 to 3 ppm Range, Model MN-5. Values were essentially zero in all tests.

It should be noted that the above scope of work did not include microbiological studies of water samples, and that the undersigned has not been informed of previous evidence, reports, or observations of potential microbiological activity and microbiological induced corrosion (MIC), presence of tubercles, biofilms, or localized mounds/erosion of carbon-steel substrate to date at this project.

The laboratory chemical assay of these water specimens conducted on December 10, 2019 (4 specimens, data presented in Table 1) are in line with or similar to the chemical assay of previous Carlsbad Caverns Elev. 1&2 water specimens conducted on December 20, 2018 (4 specimens) and May 1, 2019 (8 specimens, data presented in Table 2), as well as historical data pertaining to Carlsbad Caverns water chemistries data (researched and/or made available to me).

Mundelein, Illinois 60060

Table 1 —Summary of Laboratory Data of Water Specimens (conducted Dec. 10, 2019)

Sample Description/Location pH Temp. Cond. TDS Cl¯ SO4

2- NO3

- NO2

- Mn2+

(°C) (µS/cm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm)

A’ Gutter below Beam I 125S 8.2 23.6 510 364 <30 70 10 0 0

B’ Gutter below Beam I 131S 8.1 23.3 462 328 <30 <50 2 0 0

C’ Gutter below Beam I 125S (from drip source)

7.8 23.4 471 335 <30 <10 1 0 0

D’ Gutter below Beam I 110S 8.1 23.3 1099 779 87 >200 15 0 0

Table 2 —Summary of Laboratory Data of Water Specimens (conducted Dec. 20, 2018 and May 1, 2019)

Sample Description/Location pH Temp. Cond. TDS Cl¯ SO4

2- NO3

- NO2

- Mn2+

(°C) (µS/cm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) A

(12/20/18) Pool at Gutter Drain near Beam 125S 8.4 23.8 419 298 <30

B (12/20/18)

Pool at Gutter Drain near Beam 125S 8.5 24.0 425 301 <30

C (12/20/18)

Pool at Gutter Drain near Beam 132S 8.2 24.1 468 337 <30

D (12/20/18)

Pool at Gutter Drain near Beam 132S 8.2 24.4 461 327 <30

A (5/1/19)

Pool at Gutter Drain near Beam 125S 8.2 23.1 450 320 <30 <5 2 0 0

B (5/1/19)

Pool at Gutter Drain near Beam 125S 8.2 23.1 439 312 <30 <5 3.5 0 0

C (5/1/19)

Pool at Gutter Drain near Beam 132S 8.1 23.3 495 353 <30 60 2 0 <0.1

D (5/1/19)

Pool at Gutter Drain near Beam 132S 8.1 23.3 480 342 <30 55 3.5 0 <0.1

E (5/1/19)

Shaft 1&2, Gutter on S. Wall between

I 110S and I 111S

8.2 23.3 1254 901 87 >200 10 0 <0.1

F (5/1/19)

Shaft 1&2, Gutter on S. Wall between

I 125S and I 126S

8.3 23.6 507 361 <30 60 5 0 <0.1

G (5/1/19)

Shaft 1&2, Gutter on S. Wall between

I 125S and I 126S

8.3 22.5 518 366 <30 70 5 0 0

H (5/1/19)

Shaft 1&2, Gutter on S. Wall between

I 131S and I 132S

8.5 23.5 427 306 <30 <5 2 0 <0.1

Mundelein, Illinois 60060

National Park Service, Lessoned Learned Report

Much was learned and, indeed, considered valuable, in careful review of the National Park Service Lessons Learned Report, specifically entitled, Carlsbad Caverns National Park, Carlsbad, New Mexico, Lessons Learned Report for the Structural Repair and Lead-Based Paint Abatement in Elevators 3&4 and Recommendations for the Repair of Elevators 1&2, dated February 15, 2016, authored and issued by Anderson Hallas Architects, PC. The review was useful in terms of: (a) problems encountered, (b) design considerations, and (c) operations (including safety).

Pertinent items and considerations, in part, were as follows.

1. National Park Service (NPS) and Carlsbad Caverns National Park personnel reasonably desired a suitable durable protective coating system that was also safe to the natural ecosystem (environment) and Carlsbad Caverns National Park workers and patrons during the remedial coatings construction phase.

2. The Elev. 3&4 shaft project specified coating system(s) containing hazardous coating ingredients, components, and constituents, which required strict conformance to specified safety requirements as well as contractor’s state-of-the-art knowledge of specified materials and their coatings installation trade.

3. Workmen’s possible use of equipment and materials in an unsafe manner, as the Elev. 3&4 shaft was considered to be a relative difficult-access work area with significant workspace constraints.

4. Workmen’s apparent lack of discipline or lackluster regard to safety considerations of hazardous chemical ingredients in coatings, especially given a restricted limited access area such as an elevator shaft.

5. Contractor field-applied remedial spray coating system(s) in-situ within the elevator shaft to: (a) new replacement carbon-steel beams that had been shop-coated prior to site delivery, but subsequently required some spot-coat repairs, and (b) existing carbon-steel beams in the shaft.

6. There evidently were significant contractor internal lack of oversight and corresponding departures from specification (that is, poor or insufficient Quality Control (QC)), which were neither immediately caught and communicated to vested parties nor resolved in a timely manner.

7. Furthermore, on-site daily coating inspection services were not initially fully implemented (at least not with on-going daily inspections and testing specifically in the shaft) to monitor workmanship and confirm all work done in accordance with project specifications.

8. While the contract requirements for inspection frequency and subsequent timely reporting were evidently in place for the Elev. 3&4 project, it does not seem that it was fully implemented (or initially in force) for the Elev. 3&4 construction project.

9. The contractor opined that the specified coating system was in their words rather complicated and difficult to install, but actual specified site mock-up coating system installations (implemented and conducted by a design team consultant) in-situ in the elevator shaft reportedly seemed to establish that the specified coatings system could be installed at the Elev. 3&4 shaft project.

10. The project was extended eleven months beyond the original schedule.

Mundelein, Illinois 60060

Coatings Selection Research

Technical research in preparation for selection of suitable and ultimately optimum coating systems were conducted. Listings of potential generic candidate coating systems that were considered technically feasible and might meet the needs and expectations of the client were considered. The undersigned relied on his experience and expertise in addition to thorough research and manufacturers’ technical literature and consultation prior to ultimately selecting proprietary coating system(s).

The following pertinent items were considered.

1. Additional water samples were procured by JVA and subsequently analyzed by PKA for various parameters and constituents, including chloride ion concentration, to better understand water chemistries within the Elev. 1&2 shaft project. As stated above, the chemical assay results were consistent with previous water sample batches as well as historical data pertaining to Carlsbad Caverns water chemistries. Understanding water chemistries associated with this project and Elev. 1&2 Shaft service environment(s) were helpful in subsequent research and deliberations into suitable remedial coatings and specifications for this project.

2. Various coating manufacturers' coating systems and generic coating types were researched and evaluated, including the following.

a. PPG Industries, Inc. (PPG); The Sherwin-Williams Company (SW); RPM International Inc.

(Carboline)

b. Benjamine Moore & Company; The Tnemec Company, Inc.; AkzoNobel N.V.; and Dudick Inc.

c. ZRC Worldwide

d. Termarust Technologies Inc.

e. Seal for Life Industries

3. A number of pertinent criteria were considered and evaluated in identifying best remedial coatings candidates, including, as follows.

a. Intended Service Environment

i. The top and bottom areas of Elev. 1&2 shaft are reportedly generally described as relatively dry.

ii. But it is understood that there are areas whereupon water ingress into the elevator shaft flows down the shaft from generally stated depths of about 50 to 300 feet deep from the top of the 766-ft deep shaft (counting the elevator pit).

b. Operational Considerations (for example, elevator shaft with relatively tight clearances or constrictive working areas, that is, physical constraints); this is considered significant in that Elev. 1&2 shaft is an even more restrictive physical work area than that of Elev. 3&4 shaft.

c. Degree of Expertise required by vested parties, particularly the Contractor

d. Environmental Service Conditions of Elev. 1&2 shaft (for example, ambient and surface temperatures, humidity, moisture (dampness or time of wetness), and pertinent aqueous cation and anion concentrations)

i. Ambient air temperatures reportedly range from 57 to 67 deg F, with an average of 60 deg F.

ii. Humidities reportedly range from 71 to 100 percent relative humidity, with an average of 96% R.H.

iii. Due to the existing sustained high humidity of Elev. 1&2 shaft, it is anticipated that moisture condensation conditions on carbon-steel surfaces will be typical and prevalent

Mundelein, Illinois 60060 unless an engineered controlled workspace and enclosure is implemented at this project during the construction phase, possibly in addition to engineered shaft ventilation and filtration considerations and protocols.

iv. Chloride ion concentrations range from less than 30 to 78 ppm.

v. Field data made available to us indicated the following additional aqueous service conditions: (a) 42 ppm Fl-, (b) 38 ppm Cl-, (c) 94 ppm SO4 2-, (d) 73 ppm NO3

-, and (e) pH of 7.6.

e. Safety Considerations (for example, low- or no-VOC coating components or constituents)

i. Workspace is generally considered to be that of confined space with restrictive direct access to substrates to be coated.

ii. Other vested parties are working out significance and consequences of: (a) natural radon levels within the elevator shaft, (b) specified lead abatement program for remaining carbon steel structural support members at the top and bottom regions of Elev. 1&2 shaft project, (c) possible engineered controls and enclosures for the specified abatement and remedial coatings operations, especially as pertains to containment, ventilation, filtration, and dehumidification.

iii. Hazardous, toxic, solvent, and carcinogenic ingredients were given close scrutiny during the coating selection research.

iv. Many of the low-VOC coating products were still considered to be potential health hazards to workers as well as to National Park Patrons (if the elevator shaft workspace were not effectively sealed to preclude dust and solvent vapor leakage to public spaces).

v. Lower explosive limit (LEL) of low-VOC products, given the elevator shaft environment and flammability concerns.

vi. For this reason, extremely low-VOC products were considered beneficial for this project, since even some low-VOC coating products may present a significant degree of health and safety issues (warnings and considerations).

f. Degree of potential carbon-steel corrosion, mostly, in terms of general, crevice, pitting, and galvanic mechanisms

g. Coating Performance Characteristics and Durability (for example, corrosion protection, abrasion and impact resistance)

h. Practicality, given potential difficulties and hardships during construction phase in elevator shaft (for example, suitable for steel; tolerant to accessibility constraints (schedule and/or tight space/access issues); ease of application, wettability, and drying time; tolerant of high ambient-air relative humidities and potential damp/moist steel substrate during application and subsequent cure)

i. Likelihood of Adherence to Construction Schedule, among other things

4. It should be noted that a number of proprietary coating systems were not deemed sufficient regarding some of the criteria considerations detailed above, in that they were not considered ideal or optimum candidates to meet the needs of Carlsbad Caverns National Park project and/or to withstand stressors from a durability aspect for this project and, as such, were eliminated from further consideration.

a. In general, it was difficult to find proprietary coating systems that had beneficial characteristics and properties in all criteria items considered.

b. For example, difficulty in finding coating products that could:

i. Be comprised of zero or low volatile organic compounds (VOC) for safety and health considerations (unique for cave/elevator-shaft conditions and environment)

ii. Tolerate marginal steel substrate conditions, high relative humidities, dew point, and potential moisture conditions on substrate

iii. Allow for extended potential time-of-wetness conditions while in service

Mundelein, Illinois 60060

iv. Allow for relatively fast cure in relatively cool temperature and potentially wet conditions

v. Allow for sufficient strength and hardness development to allow for anticipated potential impact and abrasion events by tradesmen during remedial coating operations and to limit damage by operating conditions after construction

vi. Ability to allow for relative easy localized repairs in years to decades ahead

vii. Among other technical issues

5. The following coatings were chosen for further consideration.

a. Carboline Carbozinc 859 VOC and Carboguard 635 (since previous history with adjacent Elev. 3&4 shaft)

i. The (Elev. 3&4 shaft) specified and installed (circa 2010) high-performance remedial coating system(s) consisted of solvent components and chemical compound ingredients that had some flammability, toxicity, hazardous chemical, and carcinogenic concerns.

ii. This coating system required use of a contractor with generally highly-skilled labor, sophisticated coating equipment, and knowledge of elevator shaft (or similar constrictive) work conditions.

iii. This product was ultimately eliminated from selection due to its solvent component and strict degree of surface preparation requirement.

b. ZRC Worldwide, ZRC Zero-VOC Galvanizing Compound

i. The ZRC Zero-VOC product is a two-component water-borne alkaline zinc-rich silicate protective coating system.

ii. Zinc (the major component of ZRC Zero-VOC Galvanizing Compound) is chemically relatively stable in aqueous pH values between 6 to 11. The Elev. 1&2 shaft water is only slightly alkaline, which means it in and of itself is not aggressive to the hardened fully cured ZRC Zero-VOC coating film.

iii. Product Safety Data sheets (SDS) for ZRC Zero-VOC provide, in part, the following pertinent information.

1. The liquid component of this product contains silicic acid (lithium salt) and lithium hydroxide.

a. It is not classified as physical hazards or OSHA defined hazards.

b. It is classified as health hazards in regard to skin corrosion and irritation.

c. There are precautionary warnings in that the liquid component causes serious eye irritation.

d. There are no biological limit values provided.

e. Ecological information states, “The product is not classified as environmentally hazardous,” “This product is not expected to bioaccumulate,” and “No other adverse environmental effects (e.g.

ozone depletion, photochemical ozone creation potential, endocrine

Mundelein, Illinois 60060 disruption, global warming potential) are expected from this component.”

f. This product component is reportedly not regulated by government transportation departments and agencies as hazardous.

2. The unmixed powder component of this product contains zinc powder and zinc oxide.

a. It is not classified as physical or health hazards, or OSHA hazards.

b. It is identified as an environmental hazard, that is, “Hazardous to the aquatic environment, acute hazard, Category 1,” and “Hazardous to the aquatic environment, long-term hazard, Category 1.” (Please see below in the Specified Coatings Selection, Item No. 12, wherein a provision is stated to premix coatings above-ground in a controlled staging area prior to lowering fresh coating batches into the shaft work area to prevent spills and contamination to the nearby work environment during construction phase.)

c. There are further precautionary warnings in that the unmixed powder component is “Very toxic to aquatic life with long lasting effects, Very toxic to aquatic life. May form combustible dust concentrations in air.”

(Again, please see below in the Specified Coatings Selection, Item No. 12, wherein the coating material may be premixed in an above-ground controlled staging area to limit the likelihood of problems at specific elevator shaft work areas.)

d. In the same vein, Ecological Information is presented regarding Ecotoxicity, wherein it states, “Zinc in the form of particles or dust is very toxic to aquatic organisms and may cause long-term adverse effects in the environment.” (For this reason, again, as presented in the Specified Coatings Selection, Item No. 12 below, premixing coating components above ground and subsequently transporting in lightly sealed containers to elevator shaft work areas will be best efforts to prevent accidental spills at work areas, in addition to meticulous care and inspection to preclude careless attitudes, ineptitude, and unsupervised activities that could lead to egregious events and problems.)

e. This unmixed product component is similarly listed as environmentally hazardous substances by various governmental departments and agencies.

c. Termarust TR2100 and TR2200 HS HRCSA

i. The Termarust coating system is a single-component high-ratio copolymerized calcium sulfate compound that contains mineral spirits solvent component. It has similarities to coating chemistries of modified alkyds.

ii. Termarust coating system is considered to be a plausible modified-alkyd protective coatings system in some regards; but it is a very slow drying system that would require a prolonged period of time to cure; perhaps even a month or more; especially in the relatively low-temperature, high relative humidity, service environment of Elev. 1&2 shaft.

iii. This would allow for potential damage of the coating system by other trades until such time that the coating had developed sufficient integral strength characteristics to withstand a certain level of physical damage.

Mundelein, Illinois 60060

iv. The mineral spirits component, while it has a distinct solvent odor, is considered to have a significantly slow evaporation rate, and, as such, it may fortunately be present in reduced vapor concentrations within the shaft depending on air ventilation conditions and such, but one is still mindful of safety issues regarding health and toxicity (blood solubility and irritant issues).

v. As a safety precaution and in regard to regulatory data, treat as a flammable liquid.

vi. The product does have a smell of mineral spirts upon initial application and during its prolonged cure and hardening process.

vii. Product Safety Data sheets (SDS) for the Termarust coating system(s) provide, in part, the following pertinent information.

1. Mineral Spirits

a. Presents an inhalation hazard may have chronic effects upon prolonged and repeated inhalation. It may cause toxic effects.

b. No known carcinogenicity

c. Not expected to be harmful to the environment

d. A Hazard in regard to combustion and flammability. Vapor explosion hazard under right conditions

e. Toxicological information states, “May be irritation to skin, eyes, and respiratory tract,” and that target organ effects are mainly the eye

f. Ecotoxicity information states, “Not available”

g. Government Departments and Agencies in regard to transportation information, generally list as combustible or flammable liquid

2. Termarust TR2100 HRCSA Primer/Topcoat

a. Classification as flammable liquid and vapor, harmful if inhaled, causes skin irritation, causes serious eye irritation, may cause drowsiness or dizziness, may be fatal if swallowed and enters airways

b. Contains solvent naphtha (petroleum) medium aliphatic, distillates (petroleum) hydrotreated light, and Stoddard solvent

c. Toxicological information provides acute dermal, inhalation, and oral limits

d. Not classified as a carcinogen

e. Not specifically classified as toxic or hazardous to aquatic environment, explained in document as “due to partial or complete lack of data”

f. Government Departments and Agencies in regard to transportation information, generally list as flammable liquid

3. Termarust TR2200HS HRCSA Penetrant/Sealer

a. Described as a low viscosity oily liquid

b. Not considered a flammable or combustible liquid

c. May be harmful if swallowed, may cause an allergic skin reaction, causes eye irritation, and harmful if swallowed and enters airways

d. Contains dipropylene glycol dibenzoate and sulfonic acids, petroleum, calcium salts

e. Acute toxicity data is listed

Mundelein, Illinois 60060

f. Not specifically classified as toxic or hazardous to aquatic environment, explained in document as “due to partial or complete lack of data”

g. Product is reportedly not regulated by Governmental Departments and Agencies

viii. This product was ultimately eliminated from selection due to its solvent component and prolonged cure properties.

d. Fit for Life, Stopaq Tape Wrap System

i. The Stopaq Tape Wrap System consists of a Wrappingband CL corrosion protective base layer and an Outerwrap HSPEX mechanical protective outer layer.

ii. This system reportedly adheres well to wet steel surfaces, which is considered to be beneficial in regard to potential marginal or aggressive environmental conditions during the construction phase at the Elev. 1&2 Shaft project.

iii. The Stopaq Tape Wrap System is comprised of:

1. Monolithic viscous polymer-based prefabricated wrap coating with beneficial cold-flow viscoelastic properties while in service, and Portland cement and silica filler components (Wrappingband product)

2. Adhering high-density-polyethylene (HDPE) and high-tack butyl-rubber-adhesive protective rubber sheeting (Outerwrap product).

iv. A General Summary of Product Safety Data sheets (SDS) for the Stopaq Tape Wrap System provide, in part, the following pertinent information.

1. Stopaq Wrappingband CL

a. The only listed dangerous components of Wrappingband CL are quartz (SiO2) and Portland cement (which, please note, are actually embedded or encapsulated within the tape wrap layer and is thereby judged not too likely or easily to become lung-inhibitive health hazard or allergic-skin-reaction problems).

b. Solvent content is listed as 0.0 percent organic solvents and

0.00 percent VOC.

c. Aquatic toxicity data is listed as >10,000 mg/l for daphnia magna, algae – desmodesmus subspicatus, and fish – brachydanio rerio.

d. No other data is provided pertaining to Persistence and degradability, bioaccumulative potential, mobility in soil, results of PBT and vPvB assessment, or other adverse effects.

e. There are no transport information listings or specific information pertaining to Government Departments and Agencies.

f. There is no specific precautionary safety listing for regulatory information.

2. Stopaq Outerwrap HSPEX

a. Hazards and composition/information on ingredients is listed as

“Void” in that it apparently doesn’t contain harmful ingredients.

b. Similarly there are no special measures or precautions listed as to handling and storage of this product.

c. Solvent content is listed as 0.0 percent organic solvents and

0.00 percent VOC.

d. There is no specific listing of precautionary safety data pertaining to toxicological information, ecological information, transportation information, and regulatory information.

Mundelein, Illinois 60060

v. A General Summary of suitable performance characteristics (Pros) of Stopaq Tape Wrap System is as follows:

1. Provides excellent corrosion protection properties under aggressive moisture conditions.

2. Conforms to irregular shapes, has low surface tension characteristics, results in suitable adhesion properties, is surface tolerant of substrate profiles and wet conditions, and resists low temperatures and doesn’t become brittle while in service.

3. Resists impacts and indentations (and may be repaired at localized damaged areas).

4. Considered to be environmentally friendly and safe to workers and National Park patrons.

vi. A General Summary of concerns (Cons) of Stopaq Tape Wrap System is as follows:

1. This tape wrap system would likely be difficult to apply to I-Beam configurations in somewhat cramped shaft workspaces, as well as at localized restricted access spaces between beam surfaces and nearby walls.

2. Physical stretching and overlapping of tape band widths requires sustained meticulous conscientious care of workers during remedial coatings operations.

e. Generic Urethane Moisture Cure and Generic Epoxy Systems (low- or no-VOC)

i. Generally thought of as isocyanate/polyol moisture cure system (urethane).

ii. There are typically difficulties encountered with moisture cure urethane systems in near 100 percent relative humidity curing environments, for example, the curing process may be too fast, coatings may contain gross bubbles (carbon dioxide byproducts trapped within the hardened film, and such).

iii. There was not sufficient supportive technical documentation to warrant use of these types of urethane or epoxy coating systems in the Elev. 1&2 shaft environment.

6. It should be noted that spray metallized coating systems are technically feasible to protect steel, but were rather quickly eliminated from consideration due to obvious anticipated difficulties to implement such a system in a restrictive space such as an elevator shaft, as well as difficulties due to working in tight quarters and difficult access to substrates (with limited space tolerances of steel beams to be coated due to interferences from walls and such), safety considerations, and delayed impact to construction schedule. In short, zinc thermal spray operations are judged as neither practical nor feasible for this project.

Specified Coating Selection

Based on the selection process detailed herein, ultimately, ZRC Zero-VOC Galvanizing Compound was selected as a suitable (and optimum) coating recommendation for existing carbon-steel structural beam support systems at the Carlsbad Caverns Elev. 1&2 shaft project, in that it is judged to meet requirements for a safe and effective protective coating system for its intended purpose.

The following significant comments and elucidation are provided pertaining to the specification and use of ZRC Zero-VOC Galvanizing Compound protective coating system at this project.

1. Water-soluble zinc-rich inorganic silicate coating systems are considered to be one of the most important types or classification of protective coatings on the market today, especially in regard to corrosion protection of steel substrates. This generic coating system is generally a base layer applied

Mundelein, Illinois 60060 directly to bare steel and protects the metal substrate by means of galvanic cathodic protection through sacrificial corrosion of the zinc pigment (inhibitor) component rather than corrosion of the underlying steel.

2. The ZRC Zero-VOC protective coating is installed as a relatively simple one-coat system, which is considered, in fact, to be of sufficient durability in the Elev. 1&2 Shaft service environment to provide general decades long-term corrosion protection of existing carbon-steel structural supports, with periodic maintenance touch-up remediation (that is relatively easy to implement) if localized spot repairs are deemed necessary during its service life. This alkaline zinc-rich silicate protective coating serves the dual purpose of initial sacrificial galvanic cathodic corrosion protection to underlying steel followed by affording long-term, dense, hard, abrasion and impact resistant, impervious barrier coat properties in subsequent years to decades. In other words, the duration of cathodic activity of the alkaline inorganic zinc silicate protective coating is finite, in that it ultimately densifies into a long-term barrier coat. Once hardened, water exposure and dilute chloride ion concentrations actually have beneficial effects in reducing long-term corrosion of protective alkaline zinc-rich silicate films, since corrosion byproducts within the zinc silicate matrix progressively increases the passivity of the installed protective coating system.

3. A generally unique characteristic of the ZRC Zero-VOC product is that it has zero volatile organic compounds (VOC). Governmental agencies have had a dramatic influence on the coatings industry in their recognition of air pollution, toxic and unsafe chemicals, hazardous wastes (and their disposal), as well as worker and general health protections, which have had a dramatic impact on market and legislative pressure for the manufacture and use of environmentally safe lower VOC coatings. ZRC Zero-VOC Galvanizing Compound is such a coating, in fact, it could be considered an ideal coating in that it meets the desires and needs of vested parties for this project. There are significant differences amongst proprietary zinc silicate coating products; many other inorganic zinc silicate coatings and water-borne alkaline inorganic silicate coatings are considered to be relatively low VOC, but still contain solvent and additive constituents that may be considered as health and safety concerns, especially as pertains to a restrictive elevator shaft workspace at a National Park.

4. A General Summary of suitable performance characteristics (Pros) of ZRC Zero-VOC Galvanizing Compound is as follows:

a. ZRC Zero-VOC has quite limited health concerns (for example, zinc component in hardened film is considered nontoxic)

b. Ease of application (roller or brush)

c. Excellent impact and abrasion resistance, rock hard property

d. Provides cathodic protection, excellent corrosion resistance

e. Suitable for wet and freshwater immersion conditions (extended time of wetness)

f. Suitable for anticipated periodic elevator-shaft water exposures of less than 90 ppm chloride ion concentration

g. Excellent adhesion

h. Reduced maintenance costs

i. Excellent extended service life (multiple decades) with periodic inspection and maintenance

j. Excellent resistance to water

k. Dramatic resistance to undercutting

l. Installed cured alkaline zinc silicates do not shrink (other than difficulties encountered if wet-film coating is applied over 5-mils thick)

m. Strong coefficient of friction and permanent bond to steel surfaces

Mundelein, Illinois 60060

5. A General Summary of concerns (Cons) of ZRC Zero-VOC Galvanizing Compound is as follows:

a. It is relatively sensitive to prolonged initial drying characteristics if applied in low temperatures and high relative humidities.

b. This is mitigated by the fact that engineered controls of work environment and enclosures to ensure optimum conditions during remedial coating operations.

6. Zinc, and thereby the ZRC Zero-VOC protective coating, is relatively stable between a pH region of 6 to 11. Carlsbad Caverns water specimens were found to be only slightly alkaline (pH of 7.5 to 8.5), which is considered to be an ideal environment for sustained durability of the installed alkaline inorganic zinc-rich silicate protective coating system, keeping in mind that the ZRC Zero-VOC in months to years ahead during its elevator-shaft service life ultimately progressively cures and hardens into a relative dense barrier coat that further protects the underlying steel from aggressive corrosive conditions.

7. ZRC Zero-VOC is confirmed by the manufacturer to be Type 1B inorganic zinc-rich coating in accordance with SSPC Paint Specification No. 20, Zinc-Rich Primers (Type I, “Inorganic,” and Type II, “Organic”). The Carlsbad Caverns Elev. 1&2 shaft is known to have a sustained average 96 percent relative humidity and the service environment is thereby conducive to pronounced water condensation conditions. According to Paint Specification No. 20, “This primer, when applied over properly prepared steel surfaces is suitable for use on parts or structures exposed in Environmental Zones… 1B (exterior, normally dry), 2A (frequently wet by fresh water), and 2C (fresh water immersion).” Therefore, the ZRC Zero-VOC product is suitable for dry, wet, and freshwater immersion service conditions. The Carlsbad Caverns Elev. 1&2 shaft service environment is considered to have relatively minor stressors, that is, mainly high-humidity and periodic extended time of wetness.

8. ZRC Zero-VOC Galvanizing Compound has an extensive 25 to 30-year track history in relatively harsh service environments, including:

a. Use of ZRC zinc-rich topcoat product over steel railings at the Peace Bridge spanning the Niagara River between Buffalo, NY, and Fort Erie, Ontario, Canada. According to ZRC case study literature, their product was reportedly initially specified and installed for touch-up over galvanized railings in the 1960s, followed by brush installation over entire prepared railing substrates on or about 1975 and periodic maintenance. This indicates a greater than 30 to 40-year service life under what is aptly described as harsh winters, high winds, violent storms, and exposures to road salt.

b. Another ZRC Worldwide zinc-rich protective coating system highlighted in their case-study literature is a Northern California Sacramento River, U.S. Department of the Interior’s Bureau of Reclamation, comprised of an inorganic zinc silicate coated steel substrate (no topcoat) in freshwater immersive environment with reported success.

9. Given that the specified comprehensive lead paint abatement program will occur just prior to the remedial coating installation operations, it is presumed that established environmental controls and enclosures shall still be in place and utilized to preserve the pristine treated bare existing carbon-steel substrates prior to remedial coating installation. It is also beneficial if the abatement protocols allow for suitable surface profile and level of cleanliness to accommodate the specified remedial coating system.

10. Most inorganic silicates require a strict degree or level of surface preparation to result in a pristine bare steel substrate (for example, SSPC-SP5 White Metal Blast Cleaning requirement) just prior to inorganic silicate coating application in order to achieve a suitable chemical bond of the coating to its substrate and thereby maximize initial coating adhesion characteristics. So, it is best to require a conservative

Mundelein, Illinois 60060 approach to surface preparation (for example, gritblasting operations down to bare metal), especially if aggressive measures are required and taken during the specified Abatement protocols.

11. ZRC Zero-VOC Galvanizing Compound is unique in some ways from other proprietary inorganic zinc silicates in that it is somewhat more tolerant of potentially marginal surface preparation and cleanliness of steel. It too benefits from an optimum level of steel substrate cleanliness but may, in fact, be applied to bare steel that has had less effective surface preparation protocols (for example, even SSPC-SP3 Power Tool Cleaning). While the selected ZRC Zero-VOC product may be applied to lessor prepared steel substrates, it is still prudent to optimize the level of surface preparation and cleanliness of the existing carbon-steel structural supports at this project, to minimum specified requirement of SSPC- SP11 Power Tool Cleaning to Bare Metal (or greater, for example, SSPC-SP10 Near White Metal Blast Cleaning or SSPC-SP5 White Metal Blast Cleaning). In any event, it is a common adage that if the ZRC Zero-VOC coating is found to exhibit adequate initial adhesion characteristics to even marginally prepared steel then this serves as a good indication of chemical bonding to the steel and that it will provide suitable long-term protection to the underlying steel.

12. The ZRC Zero-VOC product may be proportioned and mixed above ground at a staging area prior to lowering into elevator shaft work areas, although since significant amounts of hydrogen gas is liberated upon initial mixing, it is considered prudent to allow the mixed product to dwell for at least fifteen minutes in a bucket above ground prior to loosely fitting a lid and transporting to work areas. The product has an extended pot life that is actually longer than a daily work shift. This is thought to help in regard to safety, protection of Carlsbad Caverns’ environment, and such.

13. The ZRC Zero-VOC is relatively easy to apply, even in tight working spaces, by roller or brush.

14. The chemistries involved in proper application and subsequent curing mechanisms required in order to ensure a fully cured, hardened, zinc-rich, water-borne, inorganic silicate protective coating system is heavily dependent on existing environmental conditions of the construction workspace. ZRC Zero- VOC is an alkaline water-borne self-curing zinc-rich silicate with relatively quick cure characteristics.

The applied wet-film coating must undergo immediate evaporation of its water component followed by chemical reactions to allow for conversion to a water-insoluble zinc silicate film (through absorption of atmospheric carbon dioxide). Subsequent ongoing long-term chemical reactions allow for further development of zinc/silicate-film hardness, cross-linked, dense, impervious, adherent protective properties.

15. For this reason, it is considered ideal that Lead Paint Abatement Protocols are specified prior to the remedial coating operations for designated remaining existing carbon-steel structural members at this project.

a. This justifies (or allows for) engineered controlled environments and enclosures that are suitable for complete removal of existing coatings down to pristine bare metal substrate and subsequent control of the workspace environment (for example, low relative humidity and protection from water and moisture exposures) during a holding period (that is, defined as time between lead abatement operations (and effective surface preparation) and remedial coating operations) prior to the remedial coating application to ensure optimum conditions during remedial coating installation and subsequent curing, since partially cured or under-cured coating systems can be considered a source or cause of corrosion.

b. Lowered relative humidities within environmentally controlled enclosures will help facilitate initial drying of the fresh alkaline silicate coating system and thus optimize the resultant cure of the remedial protective coating system.

Mundelein, Illinois 60060

c. The engineered environmental enclosure may also further protect the installed remedial protective coating system (during initial cure) from mechanical damage from other concurrent competing trades working in the elevator shaft (for example, elevator rail transport activities).

d. The enclosure, if allowed to remain in place between abatement and remedial coating operations, will minimize the likelihood of “rustback” and other forms of contamination prior to remedial coating applications.

e. It is further understood that existing project elevator shaft conditions may mandate implementation of a ventilation system to reduce levels of radon gas; an on-going, low-level, naturally occurring condition at this project within the Elev. 1&2 shaft.

16. In years to decades ahead, any localized areas in which corrosion is evident, whether at ZRC Zero-VOC coating installation at carbon-steel structural support areas or at hot-dip galvanized coating installation at elevator rail assembly areas, these areas that exhibit initial stages of rusting may be immediately repaired in the future using ZRC Zero-VOC by relatively simple means.

Field-Applied Remedial Coating Specifications

Steel Coating Specification 09 97 13 has been issued to HDR, Inc. (for technical review by vested parties) on behalf of The National Park Service, Carlsbad Caverns National Park, New Mexico. The coating specification represents a field-applied protective coating to remaining existing carbon-steel structural beam support members at the top and bottom areas of Elev. 1&2 shaft, after abatement operations to remove existing coatings down to bare steel. The field-applied steel coating specification is currently a sole source specification, primarily by virtue of the proprietary coating’s tolerance to marginally prepared surfaces and general safety. This is due to the fact that the ZRC Zero-VOC Galvanizing Compound coating product has a known field performance that is not readily duplicated by other generic alkaline zinc silicate coating products. Specifically, the ability to chemically react to marginally prepared ferrous substrates is generally unique for this type of protective coating system. It is difficult to identify a similar competitor coating product that contains zero VOC and is tolerant to marginal surface preparation and high relative humidties.

As indicated above, selection was based on performance properties and coating characteristics. While the coating specification requires a coating system supplied by a single manufacturer there is a provision for an approved equal, upon suitable design team review.

The following existing carbon-steel structural supports are currently understood to remain at the Elev. 1&2 shaft for the specified in-place remedial coating operations, as reportedly detailed in a previous Carlsbad Caverns National Park, Project Conference Call Meeting Minutes, dated December 4, 2019.

1. Top Elev. 1&2 Shaft Area

a. “All structural steel in the hoistway above the First Floor (VC Elevator Floor Level) of the

Visitor Center…”

b. “At the top of the shaft, there is a portion of the shaft below the Visitor Center Level that is concrete. The steel beams on the north and south walls below the VC level but in this concrete section are embedded into the side of those concrete walls… The beams are in good shape, so abatement in place makes more sense. There are two center beams also in this section… so it again makes sense to leave these beams in place so that all beams above one level are treated the same and abated in place.”

Mundelein, Illinois 60060

2. Bottom Elev. 1&2 Shaft Area

a. “…and below the Cave Floor (Cave Elevator Floor Level) is to remain in place, be abated, and re-coated…”

b. “At the bottom of the shaft, we had discussed leaving steel in place for one beam level above the Cave floor level… It is our opinion that this level of steel beams and columns should remain and be abated in place.”

The structural carbon-steel coating specifications include, in part, the following significant items.

1. Existing abated structural and associated steel substrates shall be field-coated in-place at top and bottom sections of a 750-ft. deep elevator shaft (Elev. 1&2 project).

2. All work shall be done in accordance with coating specification and pertinent references (for example, ASTM, Federal Codes, SSPC, NACE, and AISC).

3. Remedial coating system shall be field-applied, in-situ (in place) at designated areas within the Elev. 1&2 shaft.

4. Mock-Ups shall be prepared and installed in-place at jobsite in accordance with the coating specification, manufacturer's written technical literature, and contractor's state-of-the-art knowledge and expertise of their trade. The Mock-Ups will establish suitable application of the chosen coating system using the materials and methods utilized during actual repairs and will document and confirm adequate initial performance characteristics of the installed coating system at early cure (that is, at least 7 days).

5. The recommended coating system is ZRC Zero-VOC Galvanizing Compound as manufactured by ZRC Worldwide, Marshfield, MA. It is an inorganic, water-based, two-component Zinc-Rich coating containing 93% zinc, by weight, in the dried film. This system allows for optimum safety considerations for workers; the adjacent public; and preservation of aquatic, mammal, insect, and invertebrate wildlife in direct or indirect contact and exposure to the Elev. 1&2 shaft ecosystem/construction operations.

6. The coating system shall be applied at air, material, and substrate temperatures greater than 45 deg F and (currently specified) less than 85 percent relative humidity.

7. Substrate surfaces shall be dry (or at least best efforts to proceed only when surface conditions are judged to be dry) and substrate temperatures are above the dew point, ideally, 5 degrees F above the calculated dew point or greater. While it is acknowledged and generally agreed that the product should be applied at a maximum 85 percent relative humidity (R.H.) threshold, without engineered environmental controls (such as, enhanced forced ventilation, air filtration, and/or dehumidification) it is unlikely that this R.H. requirement can be met under current understanding of the remedial coating project environment and protocols at this time.

8. The substrate shall be free of oil, grease, loosely adhered rust and oxidized byproducts, and other potential bond-inhibiting compounds.

9. The surface shall be prepared in accordance with SSPC-SP11 (for example, power tool cleaning down to bare metal with minimum 1-mil surface profile). It is currently not confirmed whether or not the abatement procedure will be by mechanical (gritblasting) operations, waterblasting procedures, Mundelein, Illinois 60060 chemical stripper means, or a combination thereof, but the specified objective of the abatement program is understood to completely remove existing lead paint down to pristine bare metal.

10. The coating shall be Roller or Brush applied, single coat, to a 2.5 to 3.5 mils DFT. The coating system shall be properly proportioned and thoroughly mixed prior to application, with strong recommendation for…