Attachment 13 - Clarifications #2_0004.pdf

Hurricane Ridge visitor center septic system (PMIS 205653) Olympic NP Attachment 13: Clarifications #2

Additional Q&A for Solicitation #140P8320R0003 Posted with Amendment #4

Questions 1-14 and their answers are in Attachment 8.

Questions 15-40 and their answers are in Attachment 9.

Q41: Can NPS identify any roadway height restrictions on the road from Port Angeles to the Hurricane Ridge Visitor Center? A 10’ diameter 30,000 gallon tank would require a roadway clearance height of at least 14 feet.

A: There are two tunnels located on the Hurricane Ridge Road. Tunnels are approximately 19' tall at the peak and 15'-2" tall at the sides. Minimum vertical clearance is identified on drawings as 14'-5". Traffic control may be required if load height requires transport via center of roadway.

Q42: Is the pumping of the septic tank that will be abandoned included in the base bid or is it part of Option A?

A: Septic pumping of the tank to be abandoned should be included in the base bid under CLIN 2.

Pumping identified under Option A will only be awarded if necessary to prevent sewage spills caused by drainfield failure if remaining drainfield capacity is overwhelmed by influent prior to commissioning and start-up of the new system.

Q43: Is there a specific quantity of ASTM C-33 sand to be considered in the base bid? When would Option B additional ASTM C-33 be utilized?

A: Contractor should plan for placement of 36" deep ASTM C-33 sand for 15,000 square feet of infiltrative surface, additional material needed to bed or set gravelless chambers if onsite topsoil is inadequate, and a general waste or loss factor. Option B may be used if site conditions require more than 36" of ASTM C-33 sand placed below the infiltrative surface to penetrate the site's restrictive layer of soil and extend into Type 1 soil below.

Q44: The staging area identified in Attachment 8, Q1 is really limited, especially if it needs to accommodate a truck and transfer turnaround area, vehicle and equipment parking, stockpiling of materials and NPS vegetation/sod irrigation management. Would the park consider a request to expand this area?

A: We recognize that more staging area is needed to accommodate the identified needs. A revised staging area plan is shown below that identifies a 45’ radius turnaround area (may be enlarged if needed and all impacted areas are restored following construction); just over 1100 square feet of equipment and material staging area; 600 square feet of vegetation/sod storage;

and an additional 400 square feet that may be approved by park management if the impact to visitor parking is acceptable.

Q45: Has the Washington State Department of Health (DOH) provided final written comments on the Predesign Report?

A: Yes, DOH has provided written comment on the Predesign Report and approval to proceed to Engineering Report. This letter is included as Attachment 14.

Q46: Are the effluent pumps and control panel expected to meet Class 1 Division 1 requirements (i.e. explosion proof pumps, intrinsically safe control panel)?

A: All electrical components must meet applicable state or federal codes. Electrical components and wiring must comply with WAC 296-46B-501, Special occupancies NEC Class 1 locations, in accordance with WAC 246-272B-06600(19).

Q47: Is it the intent of NPS to see a design that proposes no less the 15,000 square feet of drainfield to be installed?

A: Analysis during the schematic and predesign phase indicated that wastewater is stronger than residential strength, and will likely become even more concentrated following installation of low-flow fixtures during a Visitor Center building renovation scheduled for 2021. The intent behind constructing and using a 15,000 square foot drainfield was 1) to comply with WAC 246- 272B-06350(6)(c), requiring construction of 150% of the required drainfield capacity, and 2) to reduce organic loading. Furthermore, the Predesign Report comment letter from the Washington State Department of Health (DOH) in Attachment 14 accepts this proposal. Design alternatives that propose installing less than 15,000 square feet of drainfield are acceptable to the NPS with good engineering justification that is acceptable to DOH.

Q48: Is it the intent of NPS to see a design that proposes a total septic tank volume (single or tank series) of no less than 30,000 gallons?

A: The total septic tank volume of no less than 30,000 gallons was identified as a minimum volume because WAC 246-272B-06450(4)(b)(ii) requires a minimum septic tank liquid volume of three times the daily design flow. The daily design flow is currently identified as 10,000 gallons per day; hence, the 30,000 gallon minimum tank volume. However, the Washington State Department of Health (DOH) comment letter on the Predesign Report requires use of a peaking factor to convert average daily flow to design flow, and notes that the design flow must be used to size the septic and pump tanks (see comment #6 in Attachment 14). Therefore, 30,000 gallons should be considered the minimum total septic tank volume, and more may be required if deemed necessary to accommodate peak design flow.