4.0 PROTECTION OF SURFACE WATERS AND SOILS
4.1 Naturita Enterprises
Naturita Enteprises is responsible for :
monitoring produced water in Pond 12 to confirm compliance with the Division’s criteria for beneficial use as a dust suppressant;
disclosing to the users information on the characterization of produced water ;
furnishing the users guidelines for the application of the produced water and restrictions;
monitoring the road soils to characterize levels of residual from key chemicals present in the produced waters; and
maintaining recordkeeping system with periodic reports to the Division with the records keep for one year.
Naturita Enterprises pumps produced water from Pond 12 into water trucks on a pad at the west end of Pond 12 (Figure 4.1). When Pond 12 is nearly empty, frac tanks may be placed on the pad area to receive the remaining water in Pond 12 for use when Pond 12 is being refilled with another batch of water from Pond 4 and the Division is considering approval of this new batch for beneficial use. Any spillage drains naturally back into Pond 12.
4.1.2 Oversight of Operations by Trained Staff
Naturita Enterprises assign the following responsibilities:
Corporate Officer Dianna Reams
Manager Mike Narrramore
These individuals possess expertise/experience in the management of produced water, understand the D&O Plan of Reams 80 Ponds Facility, understand the requirements of the Beneficial Use plan, and can provide training to users of the produced water as a dust suppressant.
4.2 Protection of Surface Water Qualities
Ground water quality should not be directly affected by surface applications of produced water since the application rate of produced water as a dust suppressant will be below the evaporation rate. Thus, the applied water will not have the potential to infiltrate and reach ground water. An example of how this objective will be identified is outlined below:
The typical evaporation rates (inches/day) for the Naturita area during the months of likely water applications are April (0.26), May (0.35), June (0.39), July (0.42), August (0.36), September (0.26), October (0.14), and November (0.08).
Where the produced water is applied to unpaved roads, the typical application rate will be less than 0.5 gallon/sq yd (approximately 100 barrels per mile) and equal to about 0.0887 inches/application.
On this basis, the maximum number of applications per day to the same road segment ranges from 1/day (November) to 5/day (July).
The application rate of produced water as a dust suppressant will not result in the runoff of applied produced water into adjoining surface waters of the State of Colorado. This will be accomplished in the field through application within the maximums identified above and best management practices to avoid creating pooling of water on the road surface and to not apply water within 500 ft of a stream crossing or bridge.
4.3 Limitation on Accumulation of Residuals in Surface Soils
The produced water stored in Pond 12 fails to comply with the environmental performance criterial in Regulation 8.6.2(A) and thus does not meet the Division Unrestricted Use Levels (UULs). However, the Division approved alternative beneficial use criteria (Restricted Use Levels, RULs) in which Naturita Enterprises may distribute water containing constituents at concentrations greater than the UULs. Under the RULs, restrictions are applied to the use, and Naturita Enterprises is responsible for gathering data on roads where produced water is applied to ensure constituent concentrations in soil do not exceed RULs as a result of land application of the produced water. In essence, the Division is allowing Naturita Enterprises to impact soil with produced water to the lower of RULs or groundwater protection values, given that commercially-approved alternative dust suppressants likely add constituents to roads in a similar manner.
Since Naturita Enterprises prepared the original Beneficial Use Plan in 2014, the Division has replaced the CSEV table used in that plan with the EPA’s Regional Screening Levels (RULs) and Groundwater Protection Levels in the Groundwater Protection Values (GPV) soil cleanup table. The tests listed in the RULs and GPV tables will be utilized to characterize the receiving soils where produced water from Pond 12 is applied for dust suppression.
4.3.1 Calculation of Limitation for Number of Applications per Road Segment
The Restricted Use Levels for Residential Soils (RULs) provide limitations on the number of applications of produced water that can be applied to a road segment; for example:
RUL = for comparison, background level in road soils + (amount contained in each application
times the number of applications
Using road soil data for manganese (from Pilot Project 2015), the maximum number of applications can be calculated as follows (see approach in Table 3.5)
Background amount in road soils
Volume of soil receiving application = 4.41 kg
Manganese level = 1,000 mg/kg
Amount = 1,000 mg/kg x 4.41 kg = 4,410 mg
Amount added per produced water application
Manganese concentration in produced water = 74.5 mg/l
Application volume = 1.89 liters
Amount of manganese per application = 74.5 mg/l x 1.89 liters = 140.8 mg
Amount allowed in soil = RUL
RUL = 1,800 mg/kg
Amount = 1,800 mg/kg x 4.41 kg = 7,938
Maximum number of applications
Maximum number of applications = RUL (mg) – Background(mg)
= 7,938 - 4,410
= 25 applications
Table 4.1 provides the estimated number of applications before the RUL is reached for the parameters that exceed the UUL (Table 3.5). The parameters with the lowest number of allowable applications are:
Thallium ( none, background level in soil exceeds RUL; see Section 184.108.40.206 for discussion
of conditions concerning thallium RUL )
Manganese (42 applications)
Radium 226+ 288 ( 43 applications)
For the rest of the parameters, 100’s to 1,000’s of applications can be made before the RUL value is approached in road soils. Thus, the key parameters to monitoring road soils after produced water applications are thallium, manganese, and radium 226/228 since they are expected to approach the RUL after the lowest number applications.
4.3.2 Monitoring of Accumulation of Residuals in Road Soils
Naturita Enterprises has implemented two efforts to monitor the increases in chemical residuals in road soils after applications of produced water to suppress dust.
Pilot Project (2015)
In the 2015 Pilot Project, soil samples were collected before and after produced water applications on a road segment in Montrose County. A detailed description of this effort is provided in Appendix 6.3.
Based on before and after comparison of soil concentrations, the residuals of four parameters were present at levels greater than 10% above the background level after two applications. These percentages and the comparison of levels with RULs are provided below
Vanadium 43 % 29.5 mg/kg RUL = 390 mg/kg
Chromium III 36 % 3.4 mg/kg RUL = 120,000 mg/kg
Arsenic 35 % 8.1 mg/kg RUL = 34 mg/kg
Barium 16 % 157 mg/kg RUL = 15,000 mg/kg
In each instance, the RULs were not exceeded.
220.127.116.11. Soil Sampling and Analysis Plan (2016)
With the commercial launch of the business in 2016 into several counties, Naturita Enterprises implemented a Soil Sampling and Analysis Plan (Appendix 6.5) to monitor the accumulation of chemical residuals from applications of produced water to suppress dust and to evaluate the level of accumulation in comparison with the RULs. The flowchart for this monitoring effort is provided in Appendix 6.5.3.
The Annual Report submitted to the Division on May 11, 2017 provided details on this road soil monitoring effort with a supplemental summary provided on May 17, 2017. As summarized in Table 4.2, produced water was applied to 156 road segments in six (6) counties.
Soil samples were collected for applications to 56 road segments. Selected soil samples have been or are in the process of being analyzed. Available results of soil analyses are provided in Table 4.3. As noted, the respective RULs are not exceeded and, thus soils are in compliance. Importantly, the thallium value was less than detect (<0.10 mg/kg) and this importance of this value was mentioned earlier in Section18.104.22.168.
The dust suppressant parameters are included in the monitoring effort to track evaluated salt accumulations due to produced water applications and not for evaluation with RULs.
4.4 De Minimus Releases
The application of this produced water to roads should not raise a potential concern about subsequent releases of voltatile hydrocarbons to the atmosphere. To date, all the BTEX concentrations in the produced water from Pond 12 have been below the following method detection levels:
Benzene <0.004 ug/l
Toluene <0.002 ug/l
Ethylbenzene <0.005 ug/l
Xylenes <0.025 ug/l
4.5 Tables and Figures
Table 4.1 Allowable Applications to Reach RUL for Parameters that Exceed UULs.