It should be understood that with over a million fracture treatments performed by the oil and gas industry, there has never been a documented case of groundwater impacts from such operations. One also should understand that drinking water rights are not regularly conveyed in oil and gas leases and operators can only offer such sampling as authorized by the owner of such rights. Thus where conducted, the New Mexico Oil & Gas Association (NMOGA) offers herein a voluntary program for baseline groundwater sampling for consideration by its members. The sampling program would satisfy three objectives:
- Inform landowners that have concern about potential impact to water well quality
- Generate baseline data representative of groundwater well conditions in the area prior to the start of drilling activities and following completion; and,
- Provide a framework for a program that generates consistent and accurate data to ensure no impact from hydraulic fracturing operations
Participation in the baseline sampling program will be strictly voluntary. Sampling protocols as suggested in industry standards may serve as guidance for developing individual sampling protocols. NMOGA strongly recommends that all such water sampling be conducted by an independent, qualified environmental consulting firm to promote credibility and transparency.
Where to Sample
As appropriate, operators will identify water wells registered with the New Mexico Office of the State Engineer within ¼ mile of the surface location of the intended oil/gas well (http://nmwrrs.ose.state.nm.us/nmwrrs/meterReport.html). Registered wells may include domestic water supply wells as well as agricultural and stock wells. Operators will contact registered well owners and solicit their written authorization to access and sample their active water wells for the purpose of obtaining a baseline water sample. Up to two wells, if present, within the radius of review should be selected for the initial sampling to be conducted prior to spud of the proposed well to be completed by hydraulically fracture.
When to Sample
It is important to collect the initial samples prior to the spud but, not more than 6 months before the spud date to allow the results of analytical testing to be evaluated and shared with the land owner. A post-completion water sample should be collected from the same water well locations not less than six months or more than one year following well completion and stimulation.
Analyses to Perform
The selected environmental analytical laboratory should comply with all EPA testing protocols including SW-846. Using a laboratory that meets the certification requirements of The NELAC Institute (TNI) provides an added level of defensibility to the data. Pre-drill and post-completion samples should be collected in laboratory provided glassware, sealed and transported under Chain of Custody protocols to the selected laboratory for analysis of:
Alkalinity (Bicarbonate & Carbonate of CaCO3); Phosphorus; (Cations) Boron, Iron, Calcium, Magnesium, Manganese and Sodium; (Anions) Bromide, Chloride, Sulfate, Nitrate, and Nitrite as N; Dissolved methane gas; (VOC) benzene, toluene, ethyl benzene & total xylenes (BTEX); and total dissolved solids. If dissolved methane exceeds 5 mg/l, consideration should be given to the use of stable isotope analysis (SIA) and compositional analysis. Physical parameters should be noted during collection including temperature, pH and specific conductance.
Methodology of Sampling
A thorough evaluation of the selected water supply system should be conducted prior to sampling with photographs, a site sketch, weather and other information noted including deviations from established sampling protocols. General well condition, elevation, description of the water system, topography, vegetation and proximity to possible contaminant sources or utilities should be noted. Sampling location should be recorded using GPS equipment capable of 3-meter accuracy.
Water samples should be collected as closely as possible to the well head without any disturbance of the actual well system, and should be collected in a location upstream of any installed water treatment system (water softener, reverse osmosis, activated carbon filtration, etc.). Flow rate should be noted, and any observed turbidity, odor, sediment, bubbles, or discoloration of the water should be noted in sample documents.
Data Management and Analysis
The importance of managing the information generated by a baseline sampling program should not be underestimated. A data management plan is highly recommended. Quality Assurance and Quality Control of both the sample collection process and laboratory analytical data should be established and rigidly adhered to.
Suggested Baseline Sampling Collected Data Elements
|Drilling Location||Well name, coordinates, spud date, plat map file.|
|Property Owner||Name, address, phone number.|
|Parcel Information||Parcel ID (Tax ID), owner name/ID, physical address (when available).|
|Sampling Location||Location name/ID, Location type (ag well, potable well, seep, etc.), coordinates.|
|Record of Communication||History of communications with landowner regarding property access, sampling, and any complaints.|
|Permission to Sample||Documentation of written permission to access the property and collect the sample.|
|Samples||Documentation of sample collection including: field notes; chains of custody; photographs, and analytical lab reports.|
|Landowner Notification||Documentation of written notification sent to the landowner containing the results of the samples collected. Some require certified mail receipts.|