A.07.23_Well_Rehab_Appendix_compressed.pdf

Appendix

Appendix A:

Maps g5ofxswh Callout Berry Bend North g5ofxswh Callout Berry Bend South g5ofxswh Callout Osage Bluff g5ofxswh Callout Shawnee Bend g5ofxswh Callout Talley Bend g5ofxswh Callout Thibaut Point g5ofxswh Callout Visitor Center g5ofxswh Callout Windsor Crossing g5ofxswh Callout Bucksaw g5ofxswh Callout Long Shoal

Appendix B:

Berry Bend North

Water Systems Engineering, Inc. 785.242.6166 http://www.h2osystems.com

20792.w.pw.p.USACE Page 3 of 10

ND - Not Detected Berry Bend Berry Bend Detection NA - Not Applicable North South Limits

* as CaCO3 mg/L mg/L pH Value 7.29 7.30 NA

Phenolphthalein Alkalinity* ND ND 4 mg/l Total Alkalinity* 320 268 4 mg/l Hydroxide Alkalinity ND ND 4 mg/l Carbonate Alkalinity ND ND 4 mg/l Bicarbonate Alkalinity 320 268 4 mg/l Total Dissolved Solids 1,310 561 1.0 mg/l Conductivity (μm or μS/cm) 1,820 780 NA ORP (mV) 235.6 228.2 NA Langelier Saturation Index (at 16°C) +0.16 +0.13 NA Total Hardness* 384 292 4 mg/l Carbonate Hardness 320 268 4 mg/l

Non Carbonate Hardness 64 24 4 mg/l Calcium* 216 180 4 mg/l Magnesium* 168 112 4 mg/l Iron (resuspended) 4.94 1.99 0.02 mg/l Sulfate (as SO4) 64 34 2 mg/l

Anaerobic Growth (%) 10 10 NA Sulfate Reducing Bacteria Negative Negative NA Fe/Mn Oxidizing Bacteria Negative Negative NA ATP (cells per ml) Initial 13,000 12,000 NA

Client: USACE Date: March 21, 2017 Lab Report No. 20792

Re: Berry Bend, Talley Bend, Visitor Center, Osage Bluff, Shawnee Bend, Thibault Point Samples dated 2/21 and 2/22/17, Operational Profile (4), PO#282941

Appendix C:

Berry Bend South

ND - Not Detected Berry Bend Berry Bend Detection NA - Not Applicable North South Limits

* as CaCO3 mg/L mg/L pH Value 7.29 7.30 NA

Phenolphthalein Alkalinity* ND ND 4 mg/l Total Alkalinity* 320 268 4 mg/l Hydroxide Alkalinity ND ND 4 mg/l Carbonate Alkalinity ND ND 4 mg/l Bicarbonate Alkalinity 320 268 4 mg/l Total Dissolved Solids 1,310 561 1.0 mg/l Conductivity (μm or μS/cm) 1,820 780 NA ORP (mV) 235.6 228.2 NA Langelier Saturation Index (at 16°C) +0.16 +0.13 NA Total Hardness* 384 292 4 mg/l Carbonate Hardness 320 268 4 mg/l

Non Carbonate Hardness 64 24 4 mg/l Calcium* 216 180 4 mg/l Magnesium* 168 112 4 mg/l Iron (resuspended) 4.94 1.99 0.02 mg/l Sulfate (as SO4) 64 34 2 mg/l

Anaerobic Growth (%) 10 10 NA Sulfate Reducing Bacteria Negative Negative NA Fe/Mn Oxidizing Bacteria Negative Negative NA ATP (cells per ml) Initial 13,000 12,000 NA

Client: USACE Date: March 21, 2017 Lab Report No. 20792

Appendix D:

Osage Bluff

20792.w.pw.p.USACE Page 4 of 10

Client: USACE Date: March 21, 2017 Lab Report No. 20792

Re: Berry Bend, Talley Bend, Visitor Center, Osage Bluff, Shawnee Bend, Thibault Point Samples dated 2/21 and 2/22/17, Operational Profile (4), PO#282941

ND - Not Detected Osage Shawnee Thibault Detection NA - Not Applicable Bluff Bend Point Limits

* as CaCO3 mg/l mg/l mg/l pH Value 7.31 7.41 7.39 NA Phenolphthalein Alkalinity* ND ND ND 4 mg/l Total Alkalinity* 312 328 272 4 mg/l Hydroxide Alkalinity ND ND ND 4 mg/l Carbonate Alkalinity ND ND ND 4 mg/l Bicarbonate Alkalinity 312 328 272 4 mg/l Total Dissolved Solids 458 609 352 1.0 mg/l Conductivity (μm or μS/cm) 636 547 489 NA ORP (mV) 317.3 281.0 262.1 NA Langelier Saturation Index (at 16°C) +0.25 +0.32 +0.14 NA Total Hardness* 312 292 292 4 mg/l Carbonate Hardness 312 292 272 4 mg/l Non Carbonate Hardness ND ND 20 4 mg/l Calcium* 188 180 132 4 mg/l Magnesium* 124 112 160 4 mg/l Iron (resuspended) 3.16 0.71 1.53 0.02 mg/l Sulfate (as SO4) 28 28 17 2 mg/l

Anaerobic Growth (%) 10 10 10 NA Sulfate Reducing Bacteria Negative Negative Negative NA Fe/Mn Oxidizing Bacteria Negative Negative Positive NA ATP (cells per ml) Initial 16,000 4,000 14,000 NA

Client: USACE Date: March 21, 2017 Lab Report No. 20792

Appendix E:

Shawnee Bend

Client: USACE Date: March 21, 2017 Lab Report No. 20792

Re: Berry Bend, Talley Bend, Visitor Center, Osage Bluff, Shawnee Bend, Thibault Point Samples dated 2/21 and 2/22/17, Operational Profile (4), PO#282941

ND - Not Detected Osage Shawnee Thibault Detection NA - Not Applicable Bluff Bend Point Limits

* as CaCO3 mg/l mg/l mg/l pH Value 7.31 7.41 7.39 NA Phenolphthalein Alkalinity* ND ND ND 4 mg/l Total Alkalinity* 312 328 272 4 mg/l Hydroxide Alkalinity ND ND ND 4 mg/l Carbonate Alkalinity ND ND ND 4 mg/l Bicarbonate Alkalinity 312 328 272 4 mg/l Total Dissolved Solids 458 609 352 1.0 mg/l Conductivity (μm or μS/cm) 636 547 489 NA ORP (mV) 317.3 281.0 262.1 NA Langelier Saturation Index (at 16°C) +0.25 +0.32 +0.14 NA Total Hardness* 312 292 292 4 mg/l Carbonate Hardness 312 292 272 4 mg/l Non Carbonate Hardness ND ND 20 4 mg/l Calcium* 188 180 132 4 mg/l Magnesium* 124 112 160 4 mg/l Iron (resuspended) 3.16 0.71 1.53 0.02 mg/l Sulfate (as SO4) 28 28 17 2 mg/l

Anaerobic Growth (%) 10 10 10 NA Sulfate Reducing Bacteria Negative Negative Negative NA Fe/Mn Oxidizing Bacteria Negative Negative Positive NA ATP (cells per ml) Initial 16,000 4,000 14,000 NA

Client: USACE Date: March 21, 2017 Lab Report No. 20792

Appendix F:

Talley Bend

20792.w.pw.p.USACE Page 2 of 10

Client: USACE Date: March 21, 2017 Lab Report No. 20792

Re: Berry Bend, Talley Bend, Visitor Center, Osage Bluff, Shawnee Bend, Thibault Point Samples dated 2/21 and 2/22/17, Operational Profile (4), PO#282941

ND - Not Detected Visitor Center Talley Bend Detection NA - Not Applicable Limits

* as CaCO3 mg/L mg/L pH Value 7.46 6.99 NA Phenolphthalein Alkalinity* ND ND 4 mg/l Total Alkalinity* 292 392 4 mg/l Hydroxide Alkalinity ND ND 4 mg/l Carbonate Alkalinity ND ND 4 mg/l Bicarbonate Alkalinity 292 392 4 mg/l Total Dissolved Solids 393 474 1.0 mg/l Conductivity (μm or μS/cm) 547 659 NA ORP (mV) 231.1 268.9 NA Langelier Saturation Index (at 16°C) +0.26 +0.05 NA Total Hardness* 240 396 4 mg/l Carbonate Hardness 240 392 4 mg/l Non Carbonate Hardness ND 4 4 mg/l Calcium* 140 200 4 mg/l Magnesium* 100 196 4 mg/l Iron (resuspended) 2.21 0.75 0.02 mg/l Sulfate (as SO4) 9 10 2 mg/l

Anaerobic Growth (%) 10 10 NA Sulfate Reducing Bacteria Negative Negative NA Fe/Mn Oxidizing Bacteria Negative Negative NA ATP (cells per ml) Initial 22,000 57,000 NA

Appendix G:

Thibaut Point

Client: USACE Date: March 21, 2017 Lab Report No. 20792

Re: Berry Bend, Talley Bend, Visitor Center, Osage Bluff, Shawnee Bend, Thibault Point Samples dated 2/21 and 2/22/17, Operational Profile (4), PO#282941

ND - Not Detected Osage Shawnee Thibault Detection NA - Not Applicable Bluff Bend Point Limits

* as CaCO3 mg/l mg/l mg/l pH Value 7.31 7.41 7.39 NA Phenolphthalein Alkalinity* ND ND ND 4 mg/l Total Alkalinity* 312 328 272 4 mg/l Hydroxide Alkalinity ND ND ND 4 mg/l Carbonate Alkalinity ND ND ND 4 mg/l Bicarbonate Alkalinity 312 328 272 4 mg/l Total Dissolved Solids 458 609 352 1.0 mg/l Conductivity (μm or μS/cm) 636 547 489 NA ORP (mV) 317.3 281.0 262.1 NA Langelier Saturation Index (at 16°C) +0.25 +0.32 +0.14 NA Total Hardness* 312 292 292 4 mg/l Carbonate Hardness 312 292 272 4 mg/l Non Carbonate Hardness ND ND 20 4 mg/l Calcium* 188 180 132 4 mg/l Magnesium* 124 112 160 4 mg/l Iron (resuspended) 3.16 0.71 1.53 0.02 mg/l Sulfate (as SO4) 28 28 17 2 mg/l

Anaerobic Growth (%) 10 10 10 NA Sulfate Reducing Bacteria Negative Negative Negative NA Fe/Mn Oxidizing Bacteria Negative Negative Positive NA ATP (cells per ml) Initial 16,000 4,000 14,000 NA

Client: USACE Date: March 21, 2017 Lab Report No. 20792

Appendix H:

Visitor Center

Client: USACE Date: March 21, 2017 Lab Report No. 20792

Re: Berry Bend, Talley Bend, Visitor Center, Osage Bluff, Shawnee Bend, Thibault Point Samples dated 2/21 and 2/22/17, Operational Profile (4), PO#282941

ND - Not Detected Visitor Center Talley Bend Detection NA - Not Applicable Limits

* as CaCO3 mg/L mg/L pH Value 7.46 6.99 NA Phenolphthalein Alkalinity* ND ND 4 mg/l Total Alkalinity* 292 392 4 mg/l Hydroxide Alkalinity ND ND 4 mg/l Carbonate Alkalinity ND ND 4 mg/l Bicarbonate Alkalinity 292 392 4 mg/l Total Dissolved Solids 393 474 1.0 mg/l Conductivity (μm or μS/cm) 547 659 NA ORP (mV) 231.1 268.9 NA Langelier Saturation Index (at 16°C) +0.26 +0.05 NA Total Hardness* 240 396 4 mg/l Carbonate Hardness 240 392 4 mg/l Non Carbonate Hardness ND 4 4 mg/l Calcium* 140 200 4 mg/l Magnesium* 100 196 4 mg/l Iron (resuspended) 2.21 0.75 0.02 mg/l Sulfate (as SO4) 9 10 2 mg/l

Anaerobic Growth (%) 10 10 NA Sulfate Reducing Bacteria Negative Negative NA

Appendix I:

Windsor Crossing

Appendix J:

Bucksaw

Appendix K:

Long Shoal

Appendix L:

Independent Laboratory

Analysis

Water Systems Engineering, Inc. An Investigative Water Consulting & Design Laboratory 3201 Labette Terrace, Ottawa, Kansas 66067 phone: 785.242.6166 fax:785.242.9411

Date: March 21, 2017

Lab Report No. 20792

Roger Weter

USACE

15968 Truman Rd Warsaw, MO 65355

Project Description: Berry Bend, Talley Bend, Visitor Center, Osage Bluff, Shawnee Bend Thibault Point, Samples dated 2/21 and 2/22/17 Operational Profile (7); PO#282941

Test Description:

The Operational Profile analysis is designed for comparative analysis of two samples, typically one static and one pumping sample. The Operational Profile utilizes a limited and time dependent series of inorganic chemical and microbiological tests to identify fouling and corrosion issues with potential impacts on the operation of the sampled well. The tests include a number of inorganic chemical parameters such as pH, total dissolved solids/conductivity, hardness, alkalinity, oxidation reduction potential (ORP), bicarbonate, carbonates, and specific ions and compounds relevant to well fouling. Biological assessment is designed to quantify the total bacterial population, assess anaerobic conditions, and identify the presence of iron related bacteria and sulfate reducing organisms. Also included are tests for Adenosine triphosphate (ATP), and a microscopic evaluation.

Testing Procedures:

All laboratory testing procedures are performed according to the guidelines set forth in Standard Methods for the Examination of Water and Wastewater as established by the American Public Health Association (APHA), American Water Works Association (AWWA), and Water Environment Federation (WEF).

Corrosion analyses are performed in accordance with the guidelines as set forth by the National Association of Corrosion Engineers (NACE). In general, these methods are approved by both the Environmental Protection Agency (EPA) and AWWA for the reporting of water and/or wastewater data.

Sample collection and shipment is the responsibility of the customer, performed according to protocol and procedures defined by the laboratory in advance of the sampling event with regards to the specific project and nature of the problem.

Disclaimer:

The data and interpretations presented are based on an evaluation of the samples and submitted data.

Conclusions reached in this report are based upon the data available at the time of submittal and the accuracy of the report depends upon the validity of information submitted. Any recommendations presented are based on laboratory and field evaluations of similar fouling occurrences within potable water systems. Further investigative efforts, such as efficiency testing, site inspection, video survey, or other evaluation methods may offer additional insight into the system’s condition and the degree of fouling present.

Client: USACE Date: March 21, 2017 Lab Report No. 20792

Re: Berry Bend, Talley Bend, Visitor Center, Osage Bluff, Shawnee Bend, Thibault Point Samples dated 2/21 and 2/22/17, Operational Profile (4), PO#282941

ND - Not Detected Visitor Center Talley Bend Detection NA - Not Applicable Limits

* as CaCO3 mg/L mg/L pH Value 7.46 6.99 NA Phenolphthalein Alkalinity* ND ND 4 mg/l Total Alkalinity* 292 392 4 mg/l Hydroxide Alkalinity ND ND 4 mg/l Carbonate Alkalinity ND ND 4 mg/l Bicarbonate Alkalinity 292 392 4 mg/l Total Dissolved Solids 393 474 1.0 mg/l Conductivity (µm or µS/cm) 547 659 NA ORP (mV) 231.1 268.9 NA Langelier Saturation Index (at 16°C) +0.26 +0.05 NA Total Hardness* 240 396 4 mg/l Carbonate Hardness 240 392 4 mg/l Non Carbonate Hardness ND 4 4 mg/l Calcium* 140 200 4 mg/l Magnesium* 100 196 4 mg/l Iron (resuspended) 2.21 0.75 0.02 mg/l Sulfate (as SO4) 9 10 2 mg/l

Anaerobic Growth (%) 10 10 NA Sulfate Reducing Bacteria Negative Negative NA

ND - Not Detected Berry Bend Berry Bend Detection NA - Not Applicable North South Limits

* as CaCO3 mg/L mg/L pH Value 7.29 7.30 NA

Phenolphthalein Alkalinity* ND ND 4 mg/l Total Alkalinity* 320 268 4 mg/l Hydroxide Alkalinity ND ND 4 mg/l Carbonate Alkalinity ND ND 4 mg/l Bicarbonate Alkalinity 320 268 4 mg/l Total Dissolved Solids 1,310 561 1.0 mg/l Conductivity (µm or µS/cm) 1,820 780 NA ORP (mV) 235.6 228.2 NA Langelier Saturation Index (at 16°C) +0.16 +0.13 NA Total Hardness* 384 292 4 mg/l Carbonate Hardness 320 268 4 mg/l

Non Carbonate Hardness 64 24 4 mg/l Calcium* 216 180 4 mg/l Magnesium* 168 112 4 mg/l Iron (resuspended) 4.94 1.99 0.02 mg/l Sulfate (as SO4) 64 34 2 mg/l

Anaerobic Growth (%) 10 10 NA Sulfate Reducing Bacteria Negative Negative NA Fe/Mn Oxidizing Bacteria Negative Negative NA ATP (cells per ml) Initial 13,000 12,000 NA

Client: USACE Date: March 21, 2017 Lab Report No. 20792

Client: USACE Date: March 21, 2017 Lab Report No. 20792

Re: Berry Bend, Talley Bend, Visitor Center, Osage Bluff, Shawnee Bend, Thibault Point Samples dated 2/21 and 2/22/17, Operational Profile (4), PO#282941

ND - Not Detected Osage Shawnee Thibault Detection NA - Not Applicable Bluff Bend Point Limits

* as CaCO3 mg/l mg/l mg/l pH Value 7.31 7.41 7.39 NA Phenolphthalein Alkalinity* ND ND ND 4 mg/l Total Alkalinity* 312 328 272 4 mg/l Hydroxide Alkalinity ND ND ND 4 mg/l Carbonate Alkalinity ND ND ND 4 mg/l Bicarbonate Alkalinity 312 328 272 4 mg/l Total Dissolved Solids 458 609 352 1.0 mg/l Conductivity (µm or µS/cm) 636 547 489 NA ORP (mV) 317.3 281.0 262.1 NA Langelier Saturation Index (at 16°C) +0.25 +0.32 +0.14 NA Total Hardness* 312 292 292 4 mg/l Carbonate Hardness 312 292 272 4 mg/l Non Carbonate Hardness ND ND 20 4 mg/l Calcium* 188 180 132 4 mg/l Magnesium* 124 112 160 4 mg/l Iron (resuspended) 3.16 0.71 1.53 0.02 mg/l Sulfate (as SO4) 28 28 17 2 mg/l

Anaerobic Growth (%) 10 10 10 NA Sulfate Reducing Bacteria Negative Negative Negative NA Fe/Mn Oxidizing Bacteria Negative Negative Positive NA ATP (cells per ml) Initial 16,000 4,000 14,000 NA

Client: USACE Date: March 21, 2017 Lab Report No. 20792

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Microscopic Evaluation:

Visitor Center: Very low amounts of visible bacterial activity with low to moderate levels of iron oxide entrained biomass. Traces of plant particulate matter and minor amounts of iron oxide were also present. No sheathed or stalked bacteria noted.

Talley Bend: Very low amounts of visible bacterial activity with low levels of iron oxide entrained biomass. Minor amounts of iron oxide were also present. No sheathed or stalked bacteria noted.

Berry Bend N: Very low amounts of visible bacterial activity with low to moderate levels of iron oxide entrained biomass. Minor amounts of iron oxide were also present.

No sheathed or stalked bacteria noted.

Berry Bend S: No visible bacterial activity was observed. Very low levels of iron oxide and traces of iron oxide entrained biomass were present. No sheathed or stalked bacteria noted.

Osage Bluff: Low amounts of visible bacterial activity with low to moderate levels of iron entrained biomass were present. Traces of crystalline debris and iron oxide were also observed. No sheathed or stalked bacteria noted.

Shawnee Bend: No visible bacterial activity was observed. Traces of iron oxide entrained biomass were present. No sheathed or stalked bacteria noted.

Thibault Point: Low amounts of visible bacterial activity including very low numbers of Gallionella were noted. Minor amounts of iron oxide and low to moderate levels of iron oxide entrained biomass were also present.

Observations:

Limited chemical analysis of samples collected from multiple wells at the USACE facilities identified relatively neutral pH values in each sample with a slightly depressed pH level recorded in the Talley Bend Well. Alkalinity levels were elevated in all samples, signifying an increased buffering capacity towards traditional disinfection techniques. Total dissolved solids (TDS) and conductivity varied greatly between samples with particularly high levels observed in the Barry Bend North Well. TDS levels in the Barry Bend North, Barry Bend South, and Shawnee Bend samples each exceeded the EPA Secondary Drinking Water level of 500 mg/l preferred for domestic water supplies.

Hardness levels were high in each sample. Corresponding calcium concentrations, as a predominant scale forming ion, were also high in each of the samples. The calculated Langelier Saturation Index (LSI), which is an indication of the calcium carbonate mineral deposition potential, noted positive values for the samples, indicating an increased potential for mineral scale development, with a tendency for calcium carbonate scale within the well systems. Given the elevated calcium levels, fluctuations in temperature, pressure, and solids content could impact the LSI, resulting in the formation of calcium carbonate scale within the borehole and near-well formation.

A high oxidation-reduction potential (ORP), measuring the available oxygen content of the water, was recorded in each sample indicating oxidative conditions.

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Iron concentrations, represented as resuspended iron, were high in the majority of the samples.

More moderate levels of iron were noted in the Shawnee Bend and Talley Bend samples. As a point of reference, resuspended iron levels, which accounts for chemically and biologically mobilized iron in the wells, above 1.0 mg/l typically indicate significant iron presence and the potential for accumulation within the well system.

Sulfate levels varied between samples but did not exceed limits typically associated with reduced water quality or decreased well performance.

Biological testing identified low levels of bacteria present within each well sample. Adenosine triphosphate (ATP) testing, a means of evaluating active bacterial populations, noted low levels of bacteria in each sample which were well within levels typically seen in active well systems. As a point of reference, active water wells typically exhibit ATP values between 10,000 and 70,000 cells per milliliter, with values in excess of 100,000 cells per milliliter generally indicating biofouling. Anaerobic growth was limited at just 10% of the total bacterial population. Testing for sulfate reducing bacteria, a specific species of anaerobic bacteria, was also negative in all samples. Measurement of anaerobic growth and sulfate reducing bacteria is important since positive results can indicate a resident population in regions of a well where low flow, anoxic conditions typically occur.

Microscopic evaluations, conducted on centrifuged aliquots of the samples, later confirmed minimal bacterial presence. Very low or no bacterial activity was noted under magnification with low accumulations of biofilm present. A very small occurrence of iron oxidizing bacteria, Gallionella, was identified in the Thibault Point Well sample. Gallionella, are a naturally occurring species of iron oxidizing bacteria known for their ability to utilize iron and manganese as energy sources and will accumulate oxidized iron and manganese in the stalks they produce.

In its attachment to iron bearing surfaces, Gallionella will pit metal surfaces in an effort to secure the iron necessary for energy. All iron bearing structures, including stainless steel, are susceptible to this form of pitting.

Interpretations:

Samples from multiple wells at the USACE facilities displayed evidence for mineral accumulation with the well structures. Water chemistry revealed oxidative conditions sufficient to expect development of metallic oxide accumulations within the well and pump over time, especially given the presence of mild or low carbon steel components within the wells.

Corresponding iron concentrations were observed to be high and are sufficient to contribute to discoloration and the development of metallic oxide accumulations.

Each of the wells also displayed positive saturation indexes signifying an over-saturated ionic environment with regards the mineral deposition. High hardness levels and corresponding calcium concentrations further signify an increased probability for calcium carbonate scale within the wells.

Biological testing of the wells suggests relatively limited bacterial populations within the current samples. However, iron oxidizing bacteria, Gallionella, were identified in Thibault Point sample.

These bacteria utilize iron and manganese as energy sources and will accumulate oxidized iron and manganese in the stalks they produce. The secreted stalks are often shed during cycling of the well, resulting in surges of red water and spikes in total iron readings. This secretion is often responsible for accumulations of iron oxide in wells and piping systems, as the distinctive stalks the bacteria produce acts to form a mat that rapidly clogs well screens and pump intakes, reducing flow into and out of wells. As accumulations of the iron-oxy-hydroxide stalks build within the well, the base layers tend to dehydrate, resulting in a harder, more dynamic iron oxide scale. This scale accumulation is a very effective mechanism for fouling within the well and

20792.w.pw.p.USACE Page 7 of 10 pump. Gallionella infestations typically result in a higher degree of required pump maintenance, due to fouling of the intakes and iron oxide accumulations within the pump bowls.

Although Sulfate-Reducing Bacteria (SRB’s) were not specifically identified in this sample set, their possible presence and contribution to fouling should not be dismissed given the history of sulfur odors within the Berry Bend North Well. SRB’s are a group of anaerobic bacteria often identified in fouled or stagnant well systems. SRB’s are identified through a presence-absence test; however their presence is readily identifiable by the distinctive hydrogen-sulfide gas that is produced by the bacteria. Sulfate-reducing bacteria obtain energy by oxidizing organic compounds and reducing sulfate (SO4

−2) to hydrogen sulfide (H2S). As the hydrogen sulfide is released, the environment often turns acidic and corrosion can develop as the H2S is mobilized up the well column. A higher occurrence and rate of detection of these bacteria could be heavily dependent upon the operational efficiency of the well in relation to sampling, with higher counts experienced after periods of prolonged inactivity.

Recommendations:

Analyses of the submitted water samples suggested that the presence of mineral accumulations within the sampled wells is likely contributing to the reported complaints of discolored water.

Although not detected in the above analysis, some of the wells also show a history of biological-related fouling issues. To address the identified concerns these wells would benefit from a combined mechanical and chemical rehabilitation, followed by a pH controlled chlorination treatment for disinfection. A post-rehabilitation video survey and pump test for comparison purposes may be also be valuable. The recommended multi-phase treatment utilizes successive phases of cleaning to address the fouling present, and is outlined below.

The use of phosphoric acid is recommended for the cleaning of each well over other acids due to several factors. Besides being a (chemically) cleaner product, phosphoric acid has been chosen to facilitate the safety of well rehabilitation efforts – reducing impacts on both the well structure and the crew. In consideration of the use of low-carbon steel components within the wells, the use of more aggressive acids, such as hydrochloric acid, is not advised as it is inclined to cause both chloride and hydrogen attack of the well structure, increasing the chance of damage, especially to aged structures. Phosphoric acid is far less corrosive to metal and can have some passivation properties of the metal with the proper chemistry. Phosphoric acid is also very effective against iron and manganese compounds because of its ability to sequester these metals.

The addition of biodispersant chemistry is also recommended in conjunction with mechanical cleaning to target the identified fouling mechanisms. “Biodispersants” are polymeric organic acids with strong dispersants, penetrating agents, and sludge and solids control properties. The organic acid portion of the chemistry effectively dissolves any biological component of the scale matrix which often times is not dissolved by strong mineral acids. Long chain polymers help with sludge control and removal from the well as well as prevent its adhesion so that it can be removed during flushing and subsequent washout.

Given the water chemistry present and buffering capacity identified, simple chlorination would have limited effectiveness against any biological fouling mechanisms present, thus it should be employed after cleaning as a means of disinfection and not as a method of rehabilitation.

Additionally, chlorine enhancing products designed to control pH levels and provide maximum efficiency of the disinfection solution is also recommended. Such products should also contain surface acting agents to assist in penetrating sediment, deposits and gravel pack material providing increased effectiveness against hidden or protected bacteria. Dispersants within the same product to control calcium, which limits effectiveness of calcium hypochlorite in hard water conditions, may also be beneficial based off of the water chemistry observed during testing. The

20792.w.pw.p.USACE Page 8 of 10 recommendation of these products is based on the well construction data, known reactivity of these products towards the identified fouling, safety and past regulatory approval of the products, as well as the reduced risk of negative impacts to the well, aquifer, and crew.

Pretreatment: Pump Removal

Remove the permanent pump and column pipe from the well, service as needed, clean.

Disassembly of the pump is recommended for effective cleaning. Following cleaning, the pump should be evaluated for corrosion and material degradation that may have occurred over time.

The motor should be evaluated for excessive wear and the need for repair. Repair or replace any damaged components or materials exhibiting signs of degradation.

All components should be disinfected with a light chlorine solution (approximately 50 ppm) prior to being returned to the well.

Pretreatment: Mechanical Agitation

Each well should be thoroughly agitated to remove fouling that has accumulated on the casing and production zone. The agitation should utilize a stiff nylon brush, or single disk surge block to disrupt and dislodge biological growth within the well column. The tool used should complement the inner diameter of the well in size, allowing sufficient tool material to contact the well structure and aid in removal of accumulated material.

Immediately following the pretreatment agitation efforts, it is very important to thoroughly purge the wells of debris and disrupted material, beginning at the very bottom of the wells and working upwards until thoroughly evacuated. Purge until visible turbidity is removed.

Evacuated material should be collected above ground and disposed of according to local and state regulations.

Chemical Treatment Phase

Following the removal of the accumulated debris within the borehole, the chemical treatment phase will be used to further clean the well column, while allowing cleaning efforts to extend into the near-well formation to open fissures and flow paths. This treatment step is designed to primarily target scale and any biological deposits within the well and the fouling potential within the near-well formation. This step should incorporate the recommended volumes of phosphoric acid and Layne’s QC-21-IS biodispersant by as outlined in Table 1. The calculated treatment volumes are based on a volume equivalent to 1.5 times the standing well volume.

Blend the solution above ground and add the chemicals into the screened portion of the well via a tremie pipe or similar delivery mechanism. Efforts to evenly distribute the solution throughout the entire well column are strongly advised. Once the solution has been introduced, begin to surge the solution throughout the entire well for 6 to 8 hours. Following surging, allow the solution to remain downhole overnight. Monitor the pH of the downhole solution and keep it at

3.0 or below during the entire treatment process.

The following day, surge the well again for 4 to 6 hours, focusing efforts on the screened sections of the well, again monitoring the pH and keeping it at 3.0 or below, adding additional phosphoric acid if needed to maintain pH. Following surging of the treatment solution, the well should be thoroughly purged of the chemicals and disrupted material. Pump the well until the pH has returned to normal (6.5 or greater), visible turbidity is zero, and the well is pumping clear.

Collect and neutralize the evacuated material above ground according to state and local regulations.

20792.w.pw.p.USACE Page 9 of 10

Disinfection

Following chemical treatment, the wells should be disinfected. Disinfection should utilize a pH-adjusted chlorination treatment of a 300 ppm chlorine level in a pH range of 6.5 to 7.0.

For the disinfection solution, mix the chemicals in this order: water, chlorine enhancer, check the pH (above 5), add chlorine. Mix lightly. Collect and test a representative sample of the disinfection solution prior to application for pH and chlorine level. If the chlorine level has fallen, add additional sodium hypochlorite in small increments to raise it to 300 ppm.

The volume of the disinfection solution should be equivalent to 3 times the standing well volume. This larger volume is utilized to flood the borehole with the disinfection solution in order to increase the effectiveness of treatment, as well as increasing the treatment area. Utilization of NSF approved chlorine enhancing chemical Layne Oximate or similar product, is strongly encouraged to aid in both effective disinfection as well as to increase the treatment area. Based on the supplied well information and laboratory data, the chlorination treatment should incorporate the chemicals outlined in the table below.

The disinfection solution should be blended above ground and introduced into the wells by a tremie pipe or similar treatment line. Efforts should be made to disperse the disinfection solution evenly throughout the well. Once the solution is placed into the well, it should be lightly agitated with a single disc surge block, to supply agitation and dispersion throughout the well column and borehole. Following agitation, check the chlorine residual within the well to ensure sufficient strength is present. If the chlorine residual has diminished below 150 ppm, add additional sodium hypochlorite to raise it to that level.

Allow the chlorine solution to remain downhole overnight. Following this period, begin evacuation of the well from the bottom, working upwards, until a minor residual (~ 50 ppm) is present and all debris has been evacuated from the well, as identified by visible turbidity. At this time, the permanent pump and column pipe can be placed back into the well and utilized to purge the remaining chlorine solution from the well.

Once disinfection efforts are completed, the well should be returned to an active operating schedule as soon as possible.

Post Treatment Monitoring and Evaluation

Follow up sampling of the wells to evaluate cleaning efforts and to establish a new baseline could aid in establishing long term well operation and maintenance procedures. A monitoring program that includes periodic submittal of water samples to the lab to assess conditions within the system would be beneficial to ensure the long-term operating efficiency of the wells, and identify fouling before it reaches severe levels.

Water Systems Engineering, Inc. An Investigative Water Consulting & Design Laboratory 3201 Labette Terrace, Ottawa, Kansas 66067 phone: 785.242.6166 fax:785.242.9411

Calculated Chemical Treatment Volumes – USACE Wells Visitor Center

(gallons)

Talley Bend (gallons)

Berry Bend North

(gallons)

Berry Bend South

(gallons)

Osage Bluff (gallons)

Shawnee Bend

(gallons)

Thibault Point

(gallons) Well Diameter 8-in 8-in 8-in 8-in 8-in 8-in 8-in Total Depth 1100-ft 800-ft 1000-ft 1100-ft 700-ft 1100-ft 1045-ft Static Water Level 161-ft 125-ft 113-ft 120-ft 40-ft 130-ft 61-ft Targeted Treatment Volume 3750 2650 3500 3850 2600 3800 3900 Targeted Disinfection Volume 7500 5300 7000 7700 5200 7600 7700 Chemical Cleaning Phosphoric Acid (75%) 160 115 180 165 130 160 165 QC-21-IS biodispersant 65 45 90 70 70 65 70 Potable water for blending 800 700 800 750 900 800 800 Well Disinfection Sodium hypochlorite (10%) 19 13 18 19 13 19 19 Oximate chlorine enhancer 33 31 34 31 24 37 31 Potable water for blending 5000 3500 4700 5000 3500 4000 4100

Please feel free to contact our offices with any questions you may have regarding this report or if we can be of further assistance.

Eric Duderstadt Chemist/Biologist Water Systems Engineering, Inc.