Causes of Low Dissolved Oxygen (DO) in Basins 1 and 2Hypolimnions of Lake Whatcom and Proposed solutions to increase DO and improve other Water Quality Properties
Prelude
Before we get into the details of “Causes of Low Dissolved Oxygen (DO) in the Lake Whatcom and
Proposed Solutions to Increase DO and Improve Water Quality Properties” please consider the following analogy to the Lake and try to create a mental picture in your mind.
Let’s take carbonated drinks as an example. You may like drinking cold soft drinks/soda pops, beer, or carbonated water, especially on a warm summer day. What happens when you open that carbonated drink container? It loses pressure and begins going flat. It loses pressure because pressure was used to force, a gas, in this case carbon dioxide (CO2), into the liquid and that contained pressure was higher than the outside atmospheric pressure; which is why you hear a “swoosh” when that pressure is released. At the same time and in the same place, you may also observe that the gas (CO2) begins to “bubble out” of the liquid. As the temperature of the liquid becomes warmer the solubility of the gas in that liquid decreases; the effect of this is that the gas separates and bubbles out of the liquid as it warms.
Like a flat soft drink, flat beer, or flat water, the lake’s water can also become” flat” when it loses its Oxygen/Dissolved Oxygen (DO) bubbles. As flat soft drinks, beer, or carbonated water lose their bubbles these drinks also lose their flavor quality and taste differently. Changes in a liquid’s quality, flavor and taste in this case, are caused by different chemical reactions which result when that gas is lost from that liquid which causes its quality to change. As the Lake loses its bubbles of DO there are different chemical reactions which occur which affect Lake Water Quality.
There are major physical, chemical, and biological causes which decrease/deplete/consume O2/DO concentration in the Lake Whatcom, which we will explore within this article. If all identified causes create a DO deficient Lake, we should be able to logically reason and develop a solution or set of solutions which can address those causes. If Lake Whatcom is deficient in DO, logic would lead us to a solution which uses O2 (Reaeration) to replenish the deficient DO lake. We will use a Problem Solving (Causal Analysis) technique to define the problem, analyze the cause and effects of the problem, develop solutions which eliminate, mitigate, or change each cause, and propose the most cost-effective solutions based upon fact-based, rigorous logic.
WWU and DOE have used data on Phosphorous, Algae, andlowDissolved Oxygenin Lake Whatcom to drive legislation to increase property taxes, and assessfees in newly created storm water districts to manage P out of Lake Whatcomvia implementing Total MaximumDaily Load(TMDL)modeling results. Both WWU and DOE are stating that the main cause for DO depletion/consumption is Algae caused by P inflow into the Lake.
EPArecommends using Causal Analysis Diagnosis Decision Information System, or CADDIS, to help scientists and engineers in the Regions, States, and Tribes to conduct causal assessments in aquatic systems. EPA Causal Analysis is based upon Kepner Trego Causal Analysis teaching (i.e., where a problem occurs vs where it does not occur; when a problem occurs vs when it does not occur, etc.)
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A Cause and Effect diagram (an evidence/fact based logic tree) begins with the problem definition/statement (Primary Effect) which needs to be very specific describing the what (Low DO), where/location (Basin 1 and 2 hypolimnion), when/time (Warmer months – Summer), and Significance (EPA 303 Impaired Body of Water). Once the problem is defined, the investigators begin asking “Why or Caused by” which leads to logic based development of a divergent (branched) series of causes and effects depicted as a chart/diagram. Investigators keep asking why or caused by until a sufficient number of causes and effects have been determined (minimum of 5 Whys). Each Cause/Effect is supported with fact based, sensed evidence. Causes can be condition causes (occur over an extended period of time) or action causes (over a shorter period of time). Problems occur when action and condition causes line up at the same time and in the same place/space. Effective solutions address the majority of causes and prevent, change, mitigate the primary effect/problem from recurring. The most effective solution(s) address(es) the action causes.
The Low DO Cause and Effect Diagram showsmajor causes of Warmer Water Temperature, Thermal Stratification, Carbon Biochemical Oxygen Demand (CBOD), Nitrification BOD (NBOD), Sediment Oxygen Demand (SOD), and Chemical Oxygen Demand (COD- i.e., metals oxidation).
Figure 1 depicts a Simplified and Condensed Cause and Effect Chart/Diagram which shows the major causes for Low O2/DO in Basin1and 2.Basin1 and 2 represent 4% of the total volume of water in Lake Whatcom.
Algaecaused primarily by phosphorus (P), and nitrogen (N)nutrient salts assimilation and digestion contribute to the CBOD by consuming DO/O2 via respiration at night and via aerobic (O2)bacterial/microbe decomposition when they die. Other sources of organic matter (CBOD) and inorganic matter (COD) in Basins 1 and 2 are sediments caused by androgenic (man) and natural sources transported into the lake by streams, creeks, rivers, storm-waterrun-off, landslides, precipitation, air,or prior historical lake usage (saw mill debris/saw dust, sunken logs, coal mine debris/fines, decomposing train trestle wooden structures and iron rails, remnants of boats which burned and sank in the lake,etc.),also consume/deplete DO via aerobic bacteria/microbe decomposition/decay/digestion processes.
(Examples of organic matter: Coal is decomposed, hardened plant (peat) containing carbon (C), hydrogen (H), oxygen (O), Nitrogen (N), ash, and sulfur (S) with minor impurities of chlorine (Cl) and sodium (Na). Logs/wood pulp contain C, O,H,N and small amounts of other elements (calcium (Ca), potassium (K), sodium (Na), magnesium (Mg), iron (Fe), and manganese (Mn). Organic matter is heterogeneous (from many different sources) and very complex. Generally,organic matter is mainly composed of C, O, N, H, and usually contains S, P, and many other elements (Na, K, Mg, Ca, Fe, etc.)
NBOD Nitrogenous Biochemical Oxygen Demand is caused by bacterial/microbial transformation of ammonia (NH3) into nitrite (NO2) and nitrate (NO3) consuming oxygen (O2, dissolved oxygen (DO)) with each step.
SOD Sediment Oxygen Demand caused by aerobic bacterial/microbe decomposition of particulate organic matter in sediment from external sources (leaf litter, particulate BOD, other plant biomass)
COD Chemical Oxygen Demand is inorganic chemical reactions which consume/require O2/DO.
Example: Metals Oxidation (Iron + DO+ H2O -> Iron Oxides (FeO and Fe2O3) “Rust”.
References:
Overview of Root Cause Analysis Techniques R. Bowen 5/18/2011
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Minnesota Pollution Control Agency; Dissolved Oxygen TMDL-Protocolsand Submittal Requirements, December 2008
Warm water temperature and thermal stratification are caused by solar radiation intensity, and longer (hrs.) _duration exposure, resulting in a decrease in DO solubility, concentration, and availability. Thermal Stratification prevents O2 atmospheric exchange between the epilimnion (upper layer of the lake) and the hypolimnion (lower layer of the lake), fixing/defining a finite concentration of DO in hypolimnionand preventing reaeration of the hypolimnion in warmer months (late spring, summer, early fall) months.
DO solubility, availability, concentration, and thermal stratification are not an issue in colder, winter months due to conduction, convection, mixing, etc., which facilitates thecolder water temperatures throughout the Lake.
Low DO is understandably resolved by Mother Nature, with cold watertemps in winter months. The major source of O2/DO in Lake Whatcom in winter is atmospheric exchange between air and water, cold temperature, and early spring mixing caused by wind, current, convection/conduction, and turbulence. Although algae/phytoplankton, and other photosynthetic plants produce O2/DO in the lake, the majority of photosynthetic O2/DO is produced in warmer weather months(late spring/summer/early fall) when biological and other environmental conditions are favored(i.e., increased photosynthetic rates; biological growth/reproductive rates; enzymatic rates; metabolic rates;increased daylight hours, increased light intensities, increased nutrient salt solubility/ionic strength, etc. which are caused by warmer water temperatures.)
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Chart 1 shows the relationship of O2 (Oxygen) solubility vs water temperature. Colder water temperature yields higher DO solubility/availability/concentration.
Solutions Development: Effective solutions address the majority of causes and prevent, change, mitigate the primary effect/problem from recurring.
Solution 1. Hypolimnion Aeration via pumping Basin 3 Hypolimnion water into Basin 1 and 2 Hypolimnion
Figure 2. Pumping System Proposal for increasing DO in Basin 1 and 2
Pump water from Basin 3 hypolimnion into shallower Basin 1and 2 hypolimnionsin summer months, mimicking the effects of cold water temperature in winter months (Figure 2). Basin 3 contains 96% of Water volume in Lakeand functions as a “Heat Sink” in the lake. Basin 1and 2 hypolimnion DOconcentrationcan be improved immediately by engineering a pumping feedback loopsystem with DO/temp probes inserted into various positions/depths of the Lake.Pump thedenser, O2 rich water from the deeperBasin 3 into the bottom/hypolimnion of Basin 1and 2 to levitate/displace the warmer, less dense, O2 depleted Basins 1and 2 DO depleted water, and pump/manage this water out via Whatcom Creek. A Hypolimnion Cooling and Aeration system could be engineered to treat/filtercold “snow melt, Dense, O2 enriched water“entering Lake Whatcom Basin 3 from the Nooksack river diversion and treat/filter water exiting Lake Whatcom Basin 1 via Whatcom Creek to also help manage TMDL P into and out of Lake Whatcom.
The costs associated with implementing and managing such a pumping system will have to be determined but this solution will solve the Low DO problem removing the EPA 303 impaired body of water classification.
Decreasing water temp in Basin 1and 2 hypolimnion in the Lake in late spring and early summer months via implementing apumping/ feedback loop system like the one described above will increase DO content immediately, prevent thermal stratification, and allow atmospheric air /water O2 exchange between all layers in Basins 1and 2. Decreasing water temp in late spring and early summer months will also increase gas solubility (O2, CO2, etc.), lower nutrient (salts) solubility, decrease turbidity, decrease biological growth and reproductive rates, decrease metabolic rates, decrease cellular enzymatic rates, decrease photosynthetic rates, and decrease kinetic rates (chemistry/physics rates of reactions) - all observed/sensed and measured in winter/colder water temperature months (see Table1 on Water Temperature Effects on Water Quality).
Table 1 was created from data listed in "Fondriest Environmental, Inc: Water Temperature." Fundamentals of Environmental Measurements. 7 Feb. 2014. Web. <
Solution 2. Install “Clean Flo”Hypolimnion Laminar Flow Aeration System
Laminar Flow Inversion and Oxygenation
The most important part of CLEAN-FLO’s unique water improvement process is called “Continuous Laminar Flow Inversion and Oxygenation”. Laminar flow inversion sets the stage for other functions to take place that lead to eutrophication reversal and water quality improvement. CLEAN-FLO invented and engineered this energy efficient process for a wide range of fresh water and wastewater applications. Unlike ordinary diffused air systems, surface aerators, paddlewheels, hypolimnetic aerators, or propeller-aspirator aerators, Clean Flo process oxygenatesan entire body of water from top to bottom.
Laminar flow created by our systems is non-turbulent and will not increase suspended solids or increase turbidity. In fact, the opposite is true, suspended solids and turbidity will be reduced. Our diffusers are placed on the bottom and are not suspended above the sediments, to ensure oxygenation of the sediment-water interface. As the bubbles release from a diffuser, oxygen is transferred to the water from the bubble, and they also move water gently to the surface and across the surface where additional oxygen is absorbed by the water. CLEAN-FLO systems are designed to completely mix the surrounding waters and evenly distribute dissolved oxygen throughout the sediments for efficient microbial utilization.
Continuous laminar flow inversion oxygenates the water and removes toxic gases.
Laminar flow inversion and oxygenation carries oxygenated, toxic gas-free surface water down to the bottom where it binds phosphorus and nitrogento the sediments. This oxygenation helps purge the water of carbon dioxide (CO2), which produces an environment that promotes better water quality. Other gases such as hydrogen sulfide (H2S) and ammonia are also purged from the sediments. Oxygenation enables beneficial microorganisms to feed on bottom non-living organic sediment. It enables aquatic insects to feed on the microorganisms, and fish to inhabit the bottom waters and feed on the insects, providing a valuable natural food source to improve fish growth and health.
CLEAN-FLO laminar flow systems increase inversion of a water body to several times a day or several times a week or month. The amount of inversion depends on CLEAN-FLO’s engineering design to counteract incoming pollutants and pollutants in that particular body of water. Clean Flo systems are designed for a particular site and account for variables such as water depth and volume, basin bathymetry, water flow rates, presence of aquatic weeds and algae growth, and thickness and composition of lake sediment.
Continuous laminar flow aeration and oxygenation has provided valuable improvements in water quality and fish health and growth, while also producing reductions of nutrients, non-living organic muck, and foul odors.
Clean Flo provided upon request, cost estimates of the Clean Flo System and proposed evaluating this proposed solution on a Pilot basis. Attached are the estimates. I propose installing/testing the pilot in Basin 2 first and then decide on forward strategy basis typical water quality results which could be performed by WWU laboratory.
Basin 2 Pilot($850,000-$1,000,000 first year and $200,000 each year to operate/maintain after installation)
1. Cost (materials, labor, installation, travel, etc.) $650,000 not including site work, electrical and building to house compressor.
2. Annual maintenance- electricity, analytical testing costs, augmentation chemicals, nutrient sponge, etc. $150 - 200,000.
3. Installation timing (time of year; duration) - any time weather permitting - 2-3 weeks
4. How much time before we began see results/evidence that Clean Flo works in Basin 2? 30-60 days and will continue to improve for up to one year.
5. Examples of non-eutrophic lake installations - have to do some searching for non-eutrophic applications. Most applications are eutrophic.
6. Photos/diagrams/testimonies of successful installations - case study attached. I can also send you a basic presentation on our system and some projects/ photos if you have some way to accept a large file. (I have a copy of slide presentation and can forward upon request).
Basin 1($820,000-$1,000,000 first year and $200,000 to operate and maintain each year after installation)
1. Cost (materials, labor, installation, travel, etc.) $620,000 not including site work, electrical and building to house compressor.
2. Annual maintenance- electricity, analytical testing costs, augmentation chemicals, nutrient sponge, etc. $150 - 200,000.
In addition to the benefits delivered due to inorganic chemistry changes achieved by raising Dissolved Oxygen levels, (reduction in Iron, Manganese, etc.) we deliver interventions to direct the biochemistry and biology in favorable directions by exploiting our biotechnology expertise.
Clean Flo’s biotechnology first achieves aerobic conditions throughout the water column by destratification and oxygen restoration. Changing the predominant conditions in the water column (particularly in benthic zones) from anaerobic to aerobic is a primary change of system conditions that enables the biochemical pathways for nutrient metabolism to be directed into sustainably more beneficial outcomes.
These biochemical pathways are of two basic kinds:
•Catabolic – i.e. the breakdown of organic contaminants and nutrients
•Anabolic – i.e. the uptake of the products of the catabolic breakdown processes into the synthesis of higher-level organisms known as the “Food Chain”.
In anaerobic conditions, catabolic processes are slow, so that organic debris builds up as organic sediments. Within these sediments, anaerobic conditions are conducive to the proliferation of anaerobic organisms. This results in the sustenance of organisms such as E. coli, cryptosporidium, and protozoan parasites and pathogens such as Giardia.
The breakdown products of anaerobic digestion include toxic substances such as ammonia, hydrogen sulfide, methane, methyl mercury, etc. These substances are nutrients that support a limited “Food Chain” of algae (cyanobacteria), that proliferates opportunistically when conditions favor them (summer) resulting in algae blooms.
Cyanobacteria have a greater propensity for fixing Nitrogen from ammonia and thus excessive benthic ammonia levels, coupled with stratification are particularly conducive to Cyanobacteria Hazardous Algae Blooms. Aerobic conditions also deliver favorable organoleptic results; by eliminating hydrogen sulfide odor and taste issues are eliminated. Similarly, by eliminating Cyanobacteria the production of Geosmins (earthy taste/odor) are eliminated.
At the biochemical level Clean Flo interventions are architected off two platforms:
1.Enzymatic Digestion of accumulated organic contaminants along aerobic biochemical pathways to convert these contaminants into food substrate that favors and supports aerobic microorganisms to further expedite their breakdown.