B09_Questions___Answers_-_140P9725Q0041_-_Amend_01_0002.pdf

QUESTIONS & ANSWERS

140P9725Q0041 – Amendment 01

Q1. Section 1.3.A # 1 of the Statement of Work states that ROV equipment shall be disinfected before use in a water tank. Section 1.3.C # 1 of the Statement of Work notes that the ROV must be dedicated to potable water use only. Please clarify if ROV equipment used in seawater service can be disinfected and utilized for inspection of these tanks.

A1. Only ROV equipment that is brand new or has only operated in potable drinking water systems be may be used during this contract.

Q2. Between Sections 1.3 C and D of the Statement of Work, there is a paragraph (1.) that indicates that the report must be signed by an AMPP certified inspector. AMPP has numerous certifications (coating inspection, corrosion, cathodic protection, internal coating, etc.) and various level of certification within those specialties. What specific

AMPP certification are referring to?

A2. A Certified AMPP Coating Inspector

Q3. Section 1.3 B of the Statement of Work requires that the water in the tank be tested for chlorine before entry and dosed with chlorine if the levels are insufficient. Tank cleaning will result in the need to dispose of cleaning water which will need to be discharged to ground. We assume that you will want the chlorine in the water removed with a chlorination bazooka or some similar method. It seems counterproductive to chlorinate the water before tank cleaning and then have to remove chlorine from your effluent stream. Please advise if that is the NPS’s intent.

A3. The questioner is confusing two different things. 1) The chlorine residual and turbidity shall be measured both before ROV entry into the tank and after cleaning and inspection work is complete to verify the potable water quality in the tank has not degraded due to cleaning and inspection activities. 2) The wastewater generated by the ROV during cleaning/vacuuming inside the tank shall be dechlorinated with a ‘chlorination bazooka’ or similar equipment prior to discharge to a park designated location.

Q4. Would the NPS consider the use of coliform field test kits rather than a third party lab? Field test kits take 24-48 hours to achieve results (as do lab results). That means the field crew will be waiting for test results prior to demobilizing. Use of a third party lab could add several days to that schedule waiting for samples to be delivered to the lab) and the contractor will have little control over the temperature and handling of the sample.

A4. No, coliform testing shall be thru an approved Alaska Department of Environmental

Conservation (ADEC) laboratory.

Q5. In Section 1.3 (description of Tasks) it is mentioned "Cleaning of the tank floor will be performed with a vacuum pump and rotary bristle brush or equal". The ROV tank cleaner we have access to does not utilize rotary bristles. It uses only suction lift to remove sediment from the tank floor. Is this acceptable for your project?

A5. A vacuum pump alone is acceptable if it can remove all 15 years’ worth of accumulated sediment from the bottom of the tank.

Q6. The 10,000 gallon Savage Tank has a hatch that is listed as: 1’-2” x 2’-0”. This may be too small for our Tank Cleaning ROV to enter but should be big enough for our

Inspection ROV to enter and inspect. This tank may not be cleanable unless it is taken offline and confined space entry is performed for cleaning. An inspection of this sized tank without prior cleaning may cause sediment to be stirred up and turbidity to increase temporarily. Are you satisfied with an inspection only?

A6. Yes, tank inspection only is acceptable if it is determined that cleaning will increase the turbidity to unacceptable levels.

Q7. Is cleaning of the storage tanks side walls expected by the contractor, or only the tank floor? Cleaning of the walls, while the tank is full of water, may require special equipment and may not even be possible to clean the concrete walls without taking the tank offline and entering manually.

A7. It is expected that most of the sediment will be on the bottom of the tank. The contractor is expected to primarily/only clean the tank floors. Wall surfaces will be addressed during a repair contract at a later date.

Q8. WEAR NWAHC Fire System Tank (5000 Gal) is too small for us to clean with an ROV.

To clean and Inspect this tank, temporary removal from service and a confined space entry would be required to clean the tank manually. Is this an option?

A8. Yes, specifically only for the WEAR NWAHC Fire Tank, draining the tank and confined space entry is acceptable to manually clean and inspect the tank.

Q9. Any historical reports or document that would show an estimated depth of sediment in the tanks, or when they were most recently cleaned?

A9.

Park

Acronym Tank Name

Tank

Material

/Volume

Year last inspected General Findings

DENA Front Country Primary Tank Concrete

50,000

Trace of sediment in the bottom

Tank in generally good condition

DENA Front Country Summer Tank Steel

150,000

Trace of sediment in the bottom

Tank in generally good condition

DENA Rock Creek West Reservoir Concrete

50,500

1/4”-1/2” sediment in the bottom

Tank in generally good condition

DENA Rock Creek East Reservoir Concrete

50,500

1/4”-1/2” sediment in the bottom

Tank in generally good condition

DENA C Camp Tank Steel

70,000 n/a No inspection report found

DENA Savage Campground Tank Steel

10,000

No sediment depth provided

Tank is in fair condition

KATM

King Salmon FAA Water

Tank

Steel

83,000

1/4" sediment in the bottom

Tank in generally good condition

WEAR

N.W. Arctic Heritage Center

Fire Tank

Steel

5,000 n/a No inspection report found

Full reports will be provided to the successful contractor after contract award.