Back when all this hocus pocus started with our elected officials and the citizens of Southern Deschutes County were invited to Community forums – this article appeared with several others – I wonder why these facts are being pushed aside and NO one knows – this vote goes County Wide…. please educate yourself – your vote will make a difference not just for La Pine but all of Deschutes County for Local Rule and the Septic issues of Deschutes County!
Writen By Leon Shields – citizen of La Pine Oregon –
My first thought upon reading the USGS’s Evaluation of Approaches for Managing Nitrate Loading from On-Site Wastewater Systems near La Pine, Oregon was, “This passed peer review? Who were the peers?”
On page 14, under Ground-Water Recharge, the report states that the average use per person per day in the house is 45 gallons; I always estimated 50 so no dispute there. But it claims that 100% of that goes back into the aquifer. That is not true and I will get back to it. Under Ground-Water Discharge, Wells, the report assumes that water use outside the house is 15 gallons per day per person. Or, using their figures of 2.55 persons per household, that would be 38.25 gallons per day, or 13,961.25 gallons per household per year. I put my sprinkler in a 5 gal. bucket and turned on the water; it filled it in one minute. That is 300 gallons an hour. Assuming (a word used a lot in the report) that each household waters at least one hour every day during the 122 days from June the first through September, the total would be 36,600 gallons, which is 2.6 times their figures. Most people in the area have lawns or gardens, probably requiring watering averaging more than an hour a day. I see sprinklers running much earlier in the year and well into October, so the water use is probably far greater than my figures.
On page 19 evapotranspiration is shown as being a factor down to about ten feet. Drainfields can not be deeper than three feet and most are less than that. Also, once a drainfield forms a biomat little or no water exits through the bottom, draining out through the sidewalls at around .3 gallon per square foot of sidewall. This puts the water even closer to the surface, well above the ten feet. The fact that drainfield locations are usually visible by the increased growth and greener grass is a clear indication that not all the water and nitrates are going down to the water table. I encourage all to read the last paragraph under Simulation Models on page 57. That should be enough right there to toss out the whole report.
Also, in the ground-water recharge and discharge sections, there is no mention of the canals in the southeast part of the study area. Just south of the study area a canal takes a substantial part of the Little Deschutes River to the northeast into a series of canals that drain into Long Prairie. When the canal is opened up in the spring it raises the perched water table near the canals by several feet. A lot of this water is lost and never returns to the river. Additionally, 100% of Paulina Creek east of Hwy 97 is diverted to canals during the irrigation season. This changes the hydraulics in the area of the canals and the area of the river below the out-take of the canals. I believe this is a major omission. Also there is no mention of the artesian wells in the area. During the study period, one150 foot deep well brought the water up 5 feet above ground level, which is about 20 feet above the river. This is a clear indication that there are not just one but at least two aquifers. Also not mentioned are the areas with perched water tables, meaning there are in some areas at least three distinct water tables. When the static water level in your well is lower or higher than the surface water table, and I have seen both in the study area, it is a clear indication that there are separate water tables. My well’s static level is 18 feet, yet the perched water table is 8 feet. The aquifers in the study area, their flows into and out of, are a lot more complicated than the report shows and this needs to be studied further with people not connected in any way with any pollution study.
A scientific paper is supposed to be based on known facts, not assumptions. While reading the report I became increasingly dismayed at the number of times I encountered that word. I was going to count them, but a short time later read an article in the Newberry Eagle by Harry W Campbell of La Pine. He had someone count the use and they counted 32 times. Mister Campbell’s article should be read by anyone interested in this issue, as he covers things there is no sense in repeating here.
Pumice, volcanic in origin, is the foam from the lava of the volcano it came from, and will have the same minerals. The particles can range in size from that of clay to boulders. Most of the pumice in the study area has a gradation of coarse sand. I’m a fifth generation Central Oregonian; I have played in, excavated, bladed, compacted, watered, and gardened in pumice, and know full well that it does not act like typical sand created from weathered rock. I have argued this point with county and DEQ officials many times. In the Bulletin’s 7/17/07 article, The Unseen World of Soil, Peter Sussmann, a soil scientist with Deschutes National Forest, is quoted as saying “One of the amazing things about the ash around here is that although it is sand, it holds a lot of water, and it holds the water in place where the roots can find it.” I did a simple test and found that the pumice in the La Pine area would hold about 4 inches of water per foot, before reaching the saturation point and allowing the water to flow through. I thought that was too high and repeated the test, with the same results. With the 3 to 5 feet of pumice in the area, that means each acre would hold at least an acre foot of water. Pumice’s water retention was not figured into the report’s section on the hydrology of the area. Throughout the area there is yellow/orange pumice and white pumice. White pumice has had the iron and soft parts washed out by a high water table and will be faster draining and retain less water. It is found in old meadows and near the river. The structure of pumice is the reason for its ability to hold water. It is porous, as the gases escaping from the particles during their formation left passages into the interior of the pumice, and it has a highly irregular shape, making for a large surface area for the water to bond to. A good analogy between solid sand with rounded surfaces from weathering, and pumice, would be marbles and popcorn. Fill a glass with marbles and another with popcorn. Sprinkle water over them and you will find the water goes to the bottom of the glass with marbles but is absorbed by the popcorn. Pumice also has a very low cation exchange capacity (CEC), with white pumice at 5.9 meq (milliequivalents of exchangeable cations per one hundred grams of soil) and the yellow at 3.8 meq. A high CEC, of 100 or more, is good because many essential nutrients are positively charged and are held by the soil and less likely to be leached out. The lower the CEC the more likely the soil has a higher anion exchange capacity (AEC) and will hold onto negatively charged nutrients, which include nitrates.
The paper states that plant uptake of nutrients in a non agricultural setting is poorly understood, which is true. But instead of ignoring it the study should have brought in a soil scientist with a background in agriculture to do a study on it. Not doing this has left their study and conclusions incomplete.
For water to flow through soil the soil has to be saturated. The study area biome, like most of the western half of the county, while not desert (high desert) as some claim, is temperate, dry conifer forest. The precipitation, less than 30 inches per year, is considered low. La Pine’s average annual precipitation has been declining from over 20 inches during the 1950’s and 60’s to about 17 inches now. The humidity is low, meaning there is a high rate of evaporation. This means that the soil is seldom saturated. The drainfields, as stated above, form a biomat that slows down the movement of the water into the soil and forces it to disperse over the full length of the trenches, meaning there is little chance of saturating the soil, and since the soil is usually dryer above the point it leaches out of the trench it is wicked upward moving the nitrates closer to the surface and the plant roots. When a drainfield fails it is usually because the biomat becomes so thick that no water can leach out of the trench and then it either surfaces or backs up into the septic tank and eventually the house. Anyone who has excavated around drainfields, even failing ones, notices the soil outside of the biomat is not saturated.
There are several other things in the paper that are questionable, some of which Mister Campbell addresses in the Newberry Eagle. These all need to be addressed, and hopefully by someone with more expertise than I have.
It is well known in biology that any time there is a niche/food source that it will be utilized. Drainfields supply water, nutrients, and a higher temperature than the surrounding soil, attracting bacteria, funguses, protozoan, worms, arthropods, and plant roots. I have excavated around and even through drainfields and found them completely encased in roots. The nitrates that aren’t taken up by plants are taken up by bacteria. The claim is, it is too cold and there is no carbon. First, biological activity slows down but never ceases until it freezes, and the temperature stays well above freezing at that depth near the drainfield. Second there is plenty of carbon from the mass of roots from the trees, bitter brush, and other plants in the area and other organisms. A grain of pumice is an ideal factory for this. Pumice’s large surface area and porosity create anaerobic areas within the pits in the structure and the carbon is supplied from the various organisms, including roots, that have colonized it.
There is no question that nitrates have gotten into the ground-water but not from properly installed septic tank systems. As long as the drainfield stays above the original top soil (the land surface before the eruption of all the volcanoes in the area) there is little chance of the nitrates going down. In the 1950’s into the 70’s the temperature frequently got as cold as -40 degrees. As a result a lot of people thought they had to put their system in deep. Many of these drainfields were installed into the underlying gravel, a number of them right in La Pine. Cesspools (a lined bottomless pit that was frequently dug into the underlying gravel) also were common. Many people built cabins in the 1960’s and installed the then legal 500 gallon tank with 40 to 50 feet of drainfield. When the cabin became a year-round residence the drainfield was inadequate. While most added to the drainfield some dug a deep pit at the end of the drainfield into the gravel and filled it with rock which left the drainfield draining into the gravel. Metal tanks were the primary type of tank installed up to the 1990’s. While I have seen metal tanks that are still water-tight as old as twenty years, most develop holes by ten or twelve years. As long as the holes are on the upper part of the tank and above the original topsoil there isn’t a problem. If the bottom of the tank is into the gravel and holes develop in the bottom then it can cause problems. I have pumped tanks in high water areas where water is coming into the bottom of the tank from such holes. It is these situations that have led to septage contributing to the nitrates in the water table.
The first step to alleviate the problem is for the DEQ to change the maximum depth of the drainfields from 3 feet to 2 feet and maintain at least 1 foot above the original top soil. The remaining metal tanks need to be replaced as soon as possible. Many people would like to do so but don’t have the money; the county should use the 35 million to do this and to replace drainfields that are too deep. I think the last of the cesspools have been eliminated. There probably are still some drainage pits that need to be taken care of, but most have been, with the upgrading of the systems with house sales and new building permits. In the areas where the perched water table has been or is into the pumice, above the original topsoil, standard systems are inappropriate and a sewer system is probably the best route. These areas should never have been developed in the first place and if the precipitation should increase to the levels it was in the mid 1900’s there will be a lot of people with wet feet.
In several meetings and letters it has been stated that the nitrate levels have actually declined. I don’t know if this is true or not. But another sampling of the wells should be done before any other action is taken. Over the last ten years though, hundreds of old metal tanks have been replaced and the last of the cesspools and hopefully drainage pits eliminated, so the nitrate levels could be dropping. Also the nitrates that are waiting around to pop up years from now shouldn’t be that hard to find. Let’s do some soil and water samples near/under the drainfields and see if they are there.
It is interesting that the time frame for the nitrates to show up keeps getting set back: 15-20 years, 20-25 years, and now 100years. It sounds like they are not too sure of their study.