Attachment_A_-_Final_Questions_and_Answers-RFQ_140G0226Q0178_0001.pdf

Attachment A

Final Questions and Answers

RFQ 140G0226Q0178

Blanket Purchase Agreement (BPA) for acid vials containingpre-filled acid solutions for

USGS, National Water QualityLaboratory (NWQL) for use in Water Resource

Discipline(WRD) water sampling and testing programs.

1. Question #1:

Could you share more details about the methods mentioned in the specifications for:

o 4.5N Sulfuric Acid (High-temp oxidation, all colorimetric methods) o 6N (1:1) OmniTrace HCl Solution (CVAF method)

USGS’s Response:

“Please see the amended table below including two additional columns: 1) method description and 2) method number, for each constituent listed in the specifications for

4.5N Sulfuric Acid:

Constituents Method Report Level Method Description Method Number

Dissolved organic carbon

Hi-temp oxidation

0.23 mg/L Organic carbon (DOC), water, filtered, 0.7 um GF/F, acid-preserved, high temperature combustion oxidation and non-dispersive infrared spectroscopy

USGS OF 92-480

N-Ammonia Colorimetric 0.1 mg/L Nutrients, filtered water, acidified, alkaline-persulfate digestion, continuous flow

(CF) colorimetry

USGS WRI 03-4174

N-Nitrite +

Nitrate

Colorimetric 0.02 mg/L Nitrate + nitrite, filtered-acidified water, enzymatic reduction, Griess Reaction colorimetry, automated discrete analyzer

USGS TMR 5-B8

Phosphorous Colorimetric 0.003 mg/L Phosphorus, filtered water, acidified, acid-persulfate digestion, continuous flow

(CF) colorimetry

USEPA 365.1

For the 6N (1:1) OmniTrace HCl Solution, the mercury contamination requirement has been removed as it is no longer relevant to our field users. Mercury analysis has been discontinuted by the NWQL as of September 1, 2026.

Additional information about the methods used for the specifications for 7.5-7.7N Ultrex

Nitric Acid has been included as well for additional clarity.

Constituents Report

Level

Unit Method Description Method Number

Ag 1.0 µg/L Metals, filtered water, Inductively coupled plasma-mass spectrometry

USGS OF 92-634

Al 2.0 µg/L Elements in filtered water using collision/reaction cell inductively coupled plasma-mass spectrometry

USGS TMR 5-B1

As 0.1 µg/L Elements in filtered water using collision/reaction cell inductively coupled plasma-mass spectrometry

USGS TMR 5-B1

B 2.0 µg/L Metals, filtered water, add, Inductively coupled plasma-atomic emission spectrometry

USGS OF 96-149

Ba 0.1 µg/L Metals, filtered water, Inductively coupled plasma-mass spectrometry

USGS OF 92-634

Be 0.01 µg/L Metals, filtered water, Inductively coupled plasma-mass spectrometry

USGS OF 92-634

Cd 0.03 µg/L Metals, filtered water, Inductively coupled plasma-mass spectrometry

USGS OF 92-634

Co 0.03 µg/L Elements in filtered water using collision/reaction cell inductively coupled plasma-mass spectrometry

USGS TMR 5-B1

Cr 0.5 µg/L Elements in filtered water using collision/reaction cell inductively coupled plasma-mass spectrometry

USGS TMR 5-B1

Cu 0.4 µg/L Elements in filtered water using collision/reaction cell inductively coupled plasma-mass spectrometry

USGS TMR 5-B1

Fe 5.0 µg/L Metals, filtered water, Inductively coupled plasma-atomic emission spectrometry

(NWQL)

USGS OF 93-125,

p 101

Li 0.15 µg/L Metals in Water by ICP-MS (NWQL) USGS OF 92-634

K 0.004 mg/L Potassium at low concentrations in filtered water by ICP-OES

Standard Method

3120 ICP

Mn 0.4 µg/L Metals, filtered water, Inductively coupled

USGS OF 92-634

Mo 0.05 µg/L Metals, filtered water, Inductively coupled

USGS OF 92-634

Ni 0.2 µg/L Elements in filtered water using collision/reaction cell inductively coupled plasma-mass spectrometry

USGS TMR 5-B1

Pb 0.03 µg/L Metals, filtered water, Inductively coupled plasma-mass spectrometry

USGS OF 92-634

Se 0.05 µg/L Elements in filtered water using collision/reaction cell inductively coupled plasma-mass spectrometry

USGS TMR 5-B1

Sb 0.06 µg/L Metals, filtered water, Inductively coupled plasma-mass spectrometry

USGS OF 92-634

Sr 0.5 µg/L Metals in Water by ICP-MS (NWQL) USGS OF 92-634

V 0.1 µg/L Elements in filtered water using collision/reaction cell inductively coupled plasma-mass spectrometry

USGS TMR 5-B1

Zn 2.0 µg/L Elements in filtered water using collision/reaction cell inductively coupled plasma-mass spectrometry

USGS TMR 5-B1

Ca 0.02 mg/L Metals, filtered water, Inductively coupled plasma-atomic emission spectrometry

(NWQL)

USGS OF 93-125,

p 101

Mg 0.01 mg/L Metals, filtered water, Inductively coupled plasma-atomic emission spectrometry

(NWQL)

USGS OF 93-125,

p 101

Na 0.04 mg/L Metals, filtered water, Inductively coupled plasma-atomic emission spectrometry

(NWQL)

USGS OF 93-125,

p 101

Silica 0.05 mg/L Metals, filtered water, Inductively coupled plasma-atomic emission spectrometry

(NWQL)

USGS OF 93-125,

p 101

U 0.03 µg/L Metals, filtered water, Inductively coupled plasma-mass spectrometry

USGS OF 92-634

W 1.0 µg/L Metals, filtered water, Inductively coupled

USGS OF 92-634

2. Question #2:

The document specifies JT Baker/Fisher materials for solution preparation. Could you please confirm whether equivalent or higher-grade (Note: The Contracting Officer redacted vendor’s name) materials can be used instead while maintaining the required specifications?

USGS’s Response: “RFQ 140G0226Q0178, Page 5, states ‘Brand Name or Equal

Products”, Section D further explains that the listed salient characteristics define the minimum essential requirements. Vendors may propose the specified brand name products or any equivalent products that meet those salient characteristics.

You may submit either the brand name or an equivalent product that satisfies the stated requirements.”

3. Question #3:

Do you recommend that we only bid on the acid vials with our brand attached?

USGS’s Response:

“Please see USGS response to Question #2 above”