Oklahoma City’s Water Quality:

A Five-Year Assessment

Andria Parler

Grade 12

1998-99

Abstract

          The purpose of this project is to combine five years of water quality research in an assessment of Oklahoma City’s water quality.  This information will help to inform city residents and businesses of the caliber of the watershed quality in Oklahoma City.

To make this assessment, forty-six sites in and around Oklahoma City were tested for pH, dissolved oxygen, phosphate phosphorous, nitrate nitrogen, and ammonia nitrogen.   These tests were conducted in accordance to the guidelines set forth in the Oklahoma Water Watch Volunteer Monitoring Handbook by the water resources board.  It was found that the watershed was generally free of pollutants, and if present, the pollutant levels did not exceed state standards.  However there are specific sites that had high levels.  These are the areas in Oklahoma City that will require immediate attention in an effort to clean the watershed. 

It is hoped that the results of this research may be beneficial to the residents of Oklahoma City and Oklahoma County.  Water is one of the most important natural resources on this earth, and we all bear a responsibility to keep it clean and available for future generations.

RESEARCH

Water is life.  Our entire existence depends on water.  We can live without food for a month but without water for only seven days.  Two thirds of the earth’s surface is covered in water.  Of this, 97% is saltwater.  Two of the remaining three percent is frozen at the north and south poles.   Half of the remaining, 0.5% is our freshwater supply.  This water, fresh and unfrozen, is found in lakes, rivers, ponds, and streams.  Obviously, it is very important for us to keep the water clean  whether it is in a lake, river, pond, or stream. (National Geographic, 1993)  (Cobb, 1986)

In tributaries, there are different types of environments and habitats.  In most tributaries, there are riffles, pools, and runs.  A riffle has a surface which is definitely broken and usually makes a sound.  A pool has a smooth surface, no or little current, and can be deep or shallow.  A run has an obvious current, may be deep or shallow, and often has a surface which may be slightly broken, but does not make any noise.  If a stream has no water in it, then it is called a dry stream.   Substrate is the type of material found at the bottom of a stream.  The different types of substrates are loose silt and clay, gravel, cobble, boulder, bedrock or hardpan clay, and particulate organic matter (rotten leaves and fragments of sticks and logs).  (Kolbe and Luedke, 1993)

The tests in this research are for dissolved oxygen, pH, phosphate phosphorous, nitrate nitrogen, and ammonia nitrogen. 

Dissolved oxygen is one of the most important tests of water quality for aquatic life.  If the dissolved oxygen levels fall below 3-5 mg/L, organisms may have difficulty reproducing, feeding or surviving.  Oxygen is added to the water by an aerating action of the wind and waves through diffusion or physical aeration.  Oxygen can also be added by the process of photosynthesis.  The oxygen producing process generally occurs at the surface of the water because of the availability of light in this area.  The presence of oxygen may be reduced if the water is too warm by reducing its solubility or if there are too many bacteria or other organisms such as algae.  The process by which these organisms reduce the amount of oxygen is called respiration.  Overabundant organisms can consume most of the dissolved oxygen in their efforts to survive.  The test used determines precisely the amount of oxygen that is dissolved in water.  The amount of oxygen that water can hold decreases as the temperature and salinity of the water increases.   The barometric pressure also determines the capacity of oxygen that water has.  When water holds all of the dissolved oxygen that it can at a given temperature, it is 100% saturated with oxygen.  If water holds half as much dissolved oxygen as it can hold at a given temperature, it is 50% saturated with oxygen.  The algae that consumes oxygen may be due to run-off from over fertilized farmland, urban runoff,   golf course runoff, or sewage effluent which contains high levels of phosphorous and nitrogen.  This algae can consume so much oxygen that “fish-kills” can occur.  (Cobb, 1986)               

Figure 1  Relationship Between Solubility of Oxygen in Water and Water

     Temperature

pH is a measure of how acidic or basic a solution is.  In solution, some molecules break apart to form hydrogen ions (H⁺) and hydroxyl ions (OH^-).  The pH scale is a means of showing which ion has the greater concentration.  At a pH of 7.0, the concentration of both ions is equal and the solution is said to be neutral.  When the pH of water is less than 7.0 there are more hydrogen ions than hydroxyl ions.  When the pH is greater than 7.0 there are more hydroxyl ions than hydrogen ions.  The pH does not increase or decrease in a linear fashion because it is calculated as the negative  logarithm of the hydrogen ion concentration.  For example, a pH of 3 is not twice as acidic as a pH of 6.   Increases are in powers of 10.  At a pH of 5, there are 10 times more H+ ions than at a pH of 6.  Therefore, a change in pH of 1 whole number is very significant and can have a great impact on the water quality of the area being sampled.  The ability of water to buffer acidic waters is measured by its alkalinity.  Generally, an aquatic organism’s ability to complete a life cycle greatly diminishes as the pH becomes greater than 9.0 or less than 5.0.  There are several factors that can affect the pH of water.   Dissolved mineral substances, aerosols or dust from the air, and man-generated wastes which are discharged or illegally dumped into a lake or stream can affect the pH of water.  (Owen and Cauthorn, 1994)

Phosphate phosphorous is present in water in many forms including organically bound phosphorous, inorganic polyphosphates and inorganic orthophosphates.  Phosphorous occurs in nature almost solely as phosphates.  Orthophosphates (PO₄^-3), in particular, occur as ions of phosphoric acid.  All inorganic phosphates are generally considered as PO₄^-3.  Phosphorus can be introduced from a variety of sources.  Phosphates are used extensively in cleaning and laundry supplies and are present in fertilizers which can be transported to a water body through storm water runoff.  Organic phosphates are formed mostly by biological processes, however, domestic sewage can also be a source of these compounds.  Phosphorus is a biological active element and therefore cycles through many states.  Phosphorus can be removed from the water by chemical precipitation to the sediments or by adsorption to clay particulates which are deposited as sediments.    Phosphates are essential to the growth of aquatic organisms.  Liebigs’s Law of the Minimum states that the element present in the lowest concentration relative to its demand is the element limiting the process at that time.  (Hart, Hart, and Craine, 1995)   Phosphorus can be the limiting nutrient to primary productivity.  When this is the case, the discharge of raw or treated wastewater, agricultural runoff or certain industrial waste waters may serve to stimulate the growth of aquatic plants (both macro and micro).  Total phosphorous concentrations in unpolluted waters are usually less than 0.1 mg/L and orthophosphates are often present at levels less than 0.01 mg/L.  (Owen and Cauthorn, 1994)

Nitrate nitrogen is a form of nitrogen which occurs in nature.  As nitrate is assimilated by algae it is reduced to ammonia.  Nitrate (NO₃^-) can be introduced into the aquatic environment through a number sources.  Some sources are sewage, septic waste, and through the transport of nitrogen-based fertilizers.  Nitrate may also be introduced into water through atmospheric deposition.  Both nitrate and nitrite (NO₂^-) generally occur in natural waters at very low concentrations with nitrate being the most and frequently less than 1 mg/L during periods of high algal productivity.  Nitrates may be found in high concentrations in groundwater.  As nitrates are reduced they become nitrites.  Nitrites are not present at high levels in natural conditions, but are an  essential nutrient for the survival of aquatic micro and macro organisms. (Owen and Cauthorn, 1994)  

Ammonia nitrogen (NH₄⁺ ammonia ion and NH₃) is a form of nitrate nitrogen in its lowest form.  Nitrogen occurs in several different “states” or forms in the aquatic environment.   Ammonia is generally produced through the decomposition of organic compounds such as leaf litter, woody debris, etc.  Ammonia may be introduced into water from various routes.  It may enter a lake or stream absorbed to some type of inorganic particle, such as a colloidal clay particle commonly found in Oklahoma, or it may enter through deposition from the atmosphere.  Ammonia is available for assimilation by algae and frequently the highest algal growth rates occur through utilization of ammonia.  Ammonia is generated in the aquatic system through heterotrophic bacteria   as a primary product of the decomposition   of organic matter, either directly from proteins or from other nitrogenous compounds.  It occurs in water mostly as NH₄⁺.  (Owen and Cauthorn, 1994)

There have been many attempts by the government to mandate clean water.  The Federal Clean Water Act is one of these.  It controls the discharges of pollutants to surface waters in the United States.  The requirements prohibit discharges unless they are authorized by specific conditions set forth in federal or state permits.  The two classes of permits are: ¹⁾ National Pollution Discharge Elimination System (NPDES) permits, which regulate point source discharges that are direct discharges to surface waters, including the oceans, and indirect discharges to sewage plants; and ²⁾ Dredge and fill permits that regulate point source discharges to navigable waters, including adjacent and isolated wetlands.  Municipal governments, companies, and individuals must obtain these permits and also comply with non-permit related requirements.  (McCutchen On-Line, 1997)  (Stewart, 1993)   These types of laws are in effect and are helping to reestablish clean water all over the United States.

Hypothesis

        When forty-six sites in Oklahoma City’s waterways are sampled and tested for levels of pH, dissolved oxygen, phosphate phosphorous, nitrate nitrogen, ammonia nitrogen, and air and water temperatures by following the guidelines of the Oklahoma City Water Resources Board, it will be found that the water quality is at an intermediate level.  At an intermediate level, the waterways will be suitable for aquatic organisms and their supporting ecosystem and have mild levels of pollutants that do not exceed state water quality standards. 

Procedure

1.     Designate test sites in Oklahoma City.

2.     Gather a water sample by gently holding the test container in the waterway until it is full. 

3.     Perform the tests for pH, dissolved oxygen, phosphate phosphorous, nitrate nitrogen, ammonia nitrogen, and air and water temperatures on site.

4.     Record this data and take observational field notes. 

5.     Report all data to the Oklahoma City Water Resources Board.

6.     Assess the water quality quantitatively by comparing data gathered at each site.

~Results~

Sites

1.     North Canadian River and Highway 4, North of Yukon.

2.     Mouth of Lake Overholser near Stinchomb Wildlife Reserve

3.     Lake Overholser east side

4.     Lake Overholser west side

5.     Mustang Creek, SW 15^th and County Line Road

6.     Campbell Creek, SW 44^th crossing

7.     Lake Hefner east side

8.     Lake Hefner west side at marina

9.     Tributary, 4^th and Meridian

10. West tributary through OKC Fairgrounds

11. Twin and Brock Creek junction, SW 18^th and Pennsylvania

12. Lightning Creek at SW 44^th and Robinson

13. Crooked Oak Creek, Grand and Eastern

14. Crutcho Creek, SE 15^th and Interstate 40

15. Tributary through Douglas Park near Martin Luther King and NE 10^th

16. North Canadian River, NE 50^th and N. Sooner Road

17. Will Rogers Park, NW 36^th and Portland

18. Deep Fork River, Hefner and Interstate 35

19. Tributary, Coltrane and E. Wilshire

20. Tributary in Edmond, 15^th and Bryant

21. Tributary, Wilshire and Martin Luther King

22. Tributary, NW 50^th and Interstate 235

23. Tributary, 122^nd and Eastern

24. Tributary, near Memorial and Post Road

25. Tributary, Interstate 44 and Airport Road

26. Tributary, Interstate 44 and SW 15^th 

27. Tributary, Reno and Fairgrounds

28. Tributary, NW 36^th and Shartel

29. Tributary, Villa and General Pershing

30. Tributary, NW 4^th and Meridian

31. Tributary, Interstate 44 and Kelly

32. Spring Creek, Memorial and Meridian

33. Tributary, NW 71^th  and Broadway Access Road

34. North Canadian River and Rockwell

35. Tributary, NW 28^th Geraldine

36. Fairgrounds at Reno

37. Crooked Oak Creek, Reno and I-40 Junction

38. 7^th and Bryant

39. Reno near Eastern

40. SW 15^th and I-44

41. NCR and Western, Wheeler Park

42. Brock Creek, SW 20^th and Western

43. NCR and NE 10^th

44. Lime Creek at Reno and Penn

45. Lightning Creek, SE 17^th and Central

46. and I-40 Junction

Conclusion

        When forty-six sites in and around Oklahoma City were tested for levels of pH, dissolved oxygen, phosphate phosphorous, nitrate nitrogen, ammonia nitrogen, and air and water temperatures, it was found that the overall water quality was at an intermediate level.  This implies that the waterways were suitable for aquatic organisms and their supporting ecosystem and had mild levels of pollutants that do not exceed state water quality standards.

          However, there were  three specific sites that continually showed high levels of pollutants.  Sites 10, 35, and 46 are impacted waterways and will require more attention in order to restore the water quality. 

          Overall, these results show that Oklahoma City has kept its watershed relatively clean.   The levels of pollutants in the waterways fell within state water quality standards.  We must continue this environmental pattern in order to ensure the safety and longevity of our water system.

Acknowledgments

        I would like to the Oklahoma Water Resources Board for their continued cooperation from 1994-1999.  In particular, I appreciate the special efforts of Ferrla March, Keith Owen, Bill Cauthorn, Paul Koenig, and Julie Cunningham of that department.  Thanks to Rich Davis of the Water and Wastewater Utilities Department, Geographic Information Systems.  I thank Marylin Kelly-St. Clair of the Oklahoma City Sanitation Department, Pollution Control.  Thanks to the North Canadian Sewage Treatment Center.  Lastly, I thank my parents for their help and support.