Class I Deep Injection Wells
August 22, 2007
Forward: I'm hoping the readers of this blog can help.
Too many water treatment facilities simply pipe their liquid waste to a municipal treatment facility or zero liquid discharge installation at great expense.
I'm trying to show the owners of facilities that generate wastewater, which includes brine, RO concentrate, reuse residuals, industrial sewerage, that they consider using deep injection wells to dispose of wastewater. Their wastewater disposal costs could be reduced by an order of magnitude and save them millions of dollars.
The following white paper is an introduction to deep injection wells (DIW's). If you know of any plants in California that might profit by considering this alternative means of wastewater disposal, please send this article to them. -- Derik Howard
Class I Deep Injection Wells
A proven, cost-effective wastewater disposal technology
The increasing cost and regulatory complications associated with wastewater disposal is a concern for many industrial facilities in the Central Valley of California.
Large volumes of wastewater, high in total dissolved solids (TDS) and inorganic chemicals can be injected into deep injection wells (DIW) at a fraction of the cost of alternative waste disposal methods, including municipal sewer, evaporation ponds and zero liquid discharge (ZLD) systems. Deep injection well technology has the added benefit of removing potential pollutants from the accessible biosphere and can reduce regulatory compliance burdens.
Many industrial facilities are installing DIWs as a safe, long-term, low cost means of disposing of liquid wastes. With a DIW system, wastewater streams with a wide range of TDS, pH and flow rates can often be economically managed in porous formations at depths of between 2,000 and 10,000 feet below ground.
DIW systems have been implemented at facilities located within the Central Valley that produce less than 100 gallons per minute (SMS Briners, Stockton), to those with a waste stream of more than 2 million gallons a day (Hilmar Cheese). Around the country, rates of 20 to more than 2,000 gpm have been economically managed with DIW systems. The average cost of operating a DIW system, capable of handling a half million to a million gallons of wastewater a day in the Central Valley, is typically projected to be $10,000 to $20,000 a month.
The advantages of DIW systems
The treatment and disposal options available to most industrial facilities that generate wastewater in California appear to be limited to either zero liquid discharge (ZLD) installations or municipal treatment facilities. In the construction of many facilities, DIW technology has been either rejected or ignored as a suitable disposal option by design and project managers because they are not core technologies offered by many wastewater treatment firms.
Although DIW systems must be properly screened for site-specific applicability, proponents of alternative wastewater disposal systems have sometimes erroneously dismissed the application of DIWs as a disposal option based on invalid perceptions. In fact, the following have been proven:
1. The permitting process is readily facilitated by the EPA;
2. Properly sited and designed wells are not particularly vulnerable to seismic events;
3. Significant injection rates are often practical;
4. For proper waste streams, injection zone plugging can be economically avoided;
5. Easy to design and maintain;
6. Little or no treatment infrastructure;
7. High water disposal rates;
8. Knowledge and technology transfer from oil & gas production;
9. Relatively inexpensive construction and operating costs;
11. Indefinite life; and
12 Minimal restriction on the quality of the injectate.
The safety and cost effectiveness of properly sited and designed DIW systems are well understood by the relatively small community of consultants, engineers, DIW owners and regulatory agencies that monitor the installation and operation of DIW systems throughout the USA. Few DIWs have failed, and these have been due to inappropriate application of the technology. The fact that 500 Class I industrial DIWs and more than 100,000 Class II oilfield wells are operating successfully in the USA is testament to the widespread applicability of the technology.
Californian oil and gas companies have demonstrated the technical feasibility of brine injection and have relied on deep injection wells (Class II wells) throughout the Central Valley for decades.
The proper siting of a DIW requires that sufficient sedimentary layers beneath a target property are present, and that they consist of thick permeable formations with a relatively impervious cap-rock. The porous layers should be capable of receiving a sufficient volume of wastewater at a sustained rate for at least 30 years. Based on thousands of oil well logs, many areas within Central California meet this criterion and are geologically suitable for the installation of DIWs.
EPA Permit for DIW's
It requires no more effort to permit a DIW system than most other wastewater treatment systems, including ZLD systems. Class I wells are relatively straightforward to permit for the injection of nonhazardous wastes into zones separated from the lower most underground source of drinking water (USDW), defined by a TDS concentration of <10,000 milligrams per liter.
The United States Environmental Protection Agency (U.S. EPA), Underground Injection Control (UIC) program grants permits for the installation of Class I DIWs. Regulations for this program are found in the Federal Code of Regulations, Title 40, Chapter 1, Parts 144 and 147 (40 CFR 144-147).
The non-hazardous liquid waste injected at most industrial and municipal facilities using DIW technology have elevated levels of TDS, nitrates, phosphates, pathogens and/or inorganic chemicals. For the effective operation of a DIW, the wastewater should have relatively low suspended solids concentrations.
Installing a DIW system
The installation of a DIW can be viewed as a six-step process as follows.
1. Feasibility study to evaluate both site geology and waste stream
2. U.S. EPA permit application
3. Injection system design
6. Operation and Maintenance
Monitoring and Reporting
The DIW operator is typically required to submit a sample of the injectate to a state certified laboratory for regular periodic characterization of the operation. Quarterly summary reports of injection volume and pressure are also required. The DIW operation and monitoring can be automated, thereby minimizing labor costs.
The average cost of a DIW system consisting of two DIWs, surface treatment and monitoring equipment, is often on the order of two million dollars. Depending on a number of variables including the pre-injection treatment requirements, if any, the operating cost is typically between $10,000 to $20,000 a month.
The above-noted $10,000 to $20,000 per month operation and maintenance cost is consistent with published values as follows. Green, et al. (1999) determined that operation and maintenance costs for a DIW system are about 8 percent of the capital costs, including electric power and treatment chemicals for corrosion and biological growth control.
A study by the University of Texas at El Paso in 2002 indicated that operation and maintenance costs including pumping and maintenance are approximately 4 percent of capital costs. Using these published values, and assuming a capital well cost of $2,000,000, the operation and maintenance costs would be between $ 80,000 and $160,000 per year (i.e., median cost of $10,000 per month). These literature values are also consistent with costs experienced by the team for the operation of disposal wells under similar conditions.
Generally, a DIW system can be permitted and installed within two to three years.
-Site-Specific Feasibility Study - 2 to 4 months
-Preparation of the U.S. EPA permit application - 6 to 9 months
-Review of permit application by the U.S. EPA - 9 to 12 months
-DIW construction and testing - 4 to 6 months
-U.S. EPA’s review and issuance of a permit to operate - 3 to 5 months
Total time required - 24 to 36 months
The capital cost of a DIW system for many facilities can be recovered within two to three years. This is primarily due to the low monthly operating costs, which are a fraction of ZLD system operating costs or the costs of disposal to a municipal wastewater treatment facility.
Attractive benefits of the technology include corporate control of dedicated waste management capacity along with reducing plant sensitivity to future regulatory changes that are likely to result in increased disposal costs over time. Additional advantages of DIWs are the low maintenance, longevity, minimal staff oversight requirements, and recognized safety of the technology.
by Derik Howard
DIW Services, LLC
Telephone: (909) 307-0270
Green, T. S. (1999) Design and costs for a system to reduce chloride levels in the Red River by shallow well collection and deep-well disposal. Environmental Geology, vol. 38, issue 2, p. 141-147.
University of Texas at El Paso (UTEP) (2002) Zero Discharge Brine Management for Desalination Plants. Desalination Research and Development Program Report No.89. US Department of the Interior, Bureau of Reclamation.
Droplet 8 - The Unmentionable Option
August 08, 2007
Forward: This Droplet explores options for dealing with the question of how to address over-allocation in the Murray Darling Basin.
Droplets explore ideas and propositions which, if developed further, might improve water use. Ideas are explored from a fundamental perspective. They search for the building blocks and concepts that one might consider using if one was able to start without being constrained by prior decisions.
The Unmentionable Option: Is there a place for an across-the-board purchase?
“Under the Plan, the Commonwealth Government will invest up to $3 billion over 10 years to address over-allocation in the MDB. Planned in conjunction with the modernisation programme, this will be achieved by providing assistance to irrigation districts to reconfigure irrigation systems and retire non viable areas (such as those at the end of isolated channels or in salt affected areas).” A National Plan for Water Security, Jan 2007
Over 10 years, the $10 billion National Plan for Water Security proposes to use $3 billion to address over-allocation in the Murray Darling Basin and to invest $5.8 billion on “modernising irrigation in Australia.” By any measure this is a lot of money and will buy a lot of water. At current market prices, $3 billion would buy around 1,500 GL of high security water or around 5,000 GL of general security water.
To put these numbers into perspective, the total cap on surface water entitlements in the Southern Connected River Murray System is 8,734 GL. Depending upon how it is measured, the intention appears to be to buy back between 15% and 30% of water entitlements in the Southern Basin. Some of the water is likely to come from connected groundwater systems but this will not change the magnitude of the proposed investment.
Another way of understanding the size of the proposed change is to look at the permanent water market. The largest amount of permanent water entitlements ever traded in one year is less than 100 GL.
Given the size of the proposed investment, what should be done first? How should the reform plan be sequenced? How should the market be used? How should irrigators be engaged in the process?
Irrigation in the 21st Century
Many of the irrigation systems present today were designed and constructed to take advantage of technologies, water delivery systems and water measurement systems from another era. The plan envisages totally different control and measurement systems.
With much less water, much less infrastructure will be necessary – especially if the system is modernised. Major changes in system configuration, in control systems and in the size and extent of distribution infrastructure can be expected. Imagine irrigation systems with fewer channels and fewer off-takes. Fully automated, total channel control systems could be the norm. Delivery charges could halve.
Sequencing the proposed reforms
With an investment of the scale proposed, there is a risk that wrong infrastructure could be modernised. Australia could end up investing in the upgrade of redundant infrastructure. Do it the wrong way around and we could end up with gold-plated irrigation systems without any water to put in them!
Somehow, some-one is going to have to work out which bits of the system can make the best use of the available water, available land and available technology. No matter how this is done, ultimately, irrigators working through the market will have their say.
Given the reality that the market ultimately will have its say, it may be more efficient to start by buying water and letting the market decide where this water should come from. Once this has been done, planning for system modernisation and reconfiguration can be undertaken with greater confidence.
The water market
The volume of entitlements involved in the Plan’s proposed voluntary buy-back is at least 15 times greater than the total amount of permanent water entitlements that have ever been traded in a year.
This observation suggests that if the Commonwealth simply stood in the market and started buying water it would need to buy-up everything offered for many years. Some market engagement is possible and could be part of the mix but, if the proposed time-lines are to be honoured, most activity would need to be off-market. Otherwise, the market would be massively distorted. During periods of rapid adjustment, it is critical that the market sends clear long-term signals about future realities.
There are two main ways that off-market purchases can be made. The first is to run a voluntary tender process. Every irrigator would be invited to indicate how much entitlement they would be prepared to sell to the Commonwealth Operator at differing prices. This option is being widely discussed and is certainly part of the solution mix.
Voluntary tender processes rely on the willingness of people to sell. With a single large political entity involved, voluntary buy-backs involve considerable gaming. The irrigators most likely to offer to sell at an acceptable price are those most likely to exit the industry and move to another location. From a regional development perspective, many communities may prefer a process that encourages local investment.
One way of retaining more of the money in a district and forcing all irrigators to consider the alternatives is to take a percentage off every water entitlement in each region. We think that it is worth seriously considering an across-the-board, pro-rata purchase of a percentage of each water entitlement in a region as a worthwhile part of the mix of strategies used to resolve over-allocation problems.
An across-the-board pro-rata purchase
There are currently around 12,000 irrigators in the Southern Connected Murray Darling System. An across-the-board pro-rata purchase would give every irrigator some money and empower them to decide whether to improve their irrigation system, buy water or invest in something else. Much of the money would be invested locally.
If $1 billion is shared equally among these 12,000 irrigators, each would receive $83,333. If $2 billion was invested in an across-the-board buyback, each would receive twice this amount with $1 billion left either for another pro-rata reduction and / or for other off-market strategies.
To avoid a sudden shock to the system and allow all to think carefully, payment could be made up-front. This could be implemented by taking the pro-rata amount of water taken off the top of every entitlement and leasing it back for two irrigation seasons at no cost. It would give each irrigator time to carefully evaluate the options, watch the market and decide on the best investment decisions to make.
If each irrigator was paid full market value, then the benefit of continued access to this water for two further seasons could be regarded as a compensation for disruption. As many would choose to buy-back water and some would choose to sell more water, all government charges associated with permanent water trades could be waived for two years. To maximise opportunities for adjustment and clearly signal a preference for extensive modernisation, part of the $3 billion could be used to pay all exit fees.
Taxation issues also need careful consideration. For some people, compulsory acquisition arrangements may be more advantageous than those that apply to the voluntary sale of an asset.
Where to from here - Getting the option mix right
The Murray Darling Basin Commission has just announced that it is prepared to buy water for the environment from willing sellers and put in place a mechanism to allow people to express an interest in doing this. As a result, we will soon know how much water is likely to be offered voluntarily and what effect this process will have on the water market.
No-one knows how much water will be made available voluntarily and how much will need to be recovered using a compulsory mechanism, but, given the size of the current market, we expect that the amount likely to be sourced voluntarily will be much less than that which the Plan proposes to acquire.
We are not suggesting that all the $3 billion should be spent in one hit via an across-the-board, pro-rata purchase with a two season lease back, but we do think that such an approach has merit and should be part of the mix of strategies used. Side by side with a standing offer to buy more water from willing sellers under the same terms and conditions, rapid progress could be made in a way that retains confidence.
Variants to consider include implementation at a slower rate and the idea that the water market could be deepened by buying back an extra 1% or each entitlement and putting this 1% back into the market so that it is deeper and starts with a significant volume of water that is available immediately for purchase.
We consider it essential that the forthcoming legislation should contain sections enabling implementation of an across-the-board pro-rata purchase. The next step is to work out how much needs to be sourced from each region.
Comments made on an earlier draft of this droplet by Drew Collins, Peter Crawford, several government officials, several irrigators and our Steering Committee are acknowledged with appreciation.
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