Directive 050 FAQs (May 2012)


Directive 050 FAQs (May 2012)

Question What are drilling wastes?
All spent drilling fluids and cuttings or solid materials carried to surface from oil and gas wells and directional holes are considered drilling wastes.

Question What are drilling fluids?
Drilling fluids (or “muds”) are used when drilling oil and gas wells and during directional underground boring activities for pipeline construction. They are pumped down the drill string and circulated back to surface carrying the “cuttings,” which are drilled-up subsurface rock and sediments.

The three types of drilling fluids systems are water based, oil based, and gas based (air, for example). Drilling fluid systems that use Directive 050 land application methods as a disposal option typically use fresh water and allow the natural clays from the drill cuttings to form a viscous fluid known as “mud.” Other additives are used to ensure efficient, productive, and safe drilling operations, and include, among others, clay, calcium nitrate, wood fibre, lubricants, iron oxides, and calcium carbonates.

Question What are cement returns?
Cement is used to set the well casings, the excess cement that flows back to surface is called cement returns. Cement returns are commonly placed in an earthen pit on the well site, allowed to harden, and then covered with one metre of subsoil. Directive 050 requires well licensees to obtain landowner consent when the pit size exceeds four square metres. This consent can be part of either the surface lease or right-of-entry agreement for the well site or an independent agreement.
Landowner agreements to bury cement returns are intended to prevent conflicts in future land development plans. Cement returns can also be sent to an approved landfill once hardened at the well site.

Question How is drilling waste disposed of?
Drilling waste can be disposed of either by using the land application methods that are set out in Directive 050 or sending it to an approved waste management facility. The principle behind land application is to allow the soil’s natural capacity to assimilate waste in a manner that preserves soil conditions. The objective is to ensure that the waste benefits the soil quality or, at a minimum, that contaminant concentrations fall within provincial soil quality guidelines.

Landspreading and mix-bury-cover are land application methods where drilling waste is mixed with subsoils and covered. These disposal options are limited to well sites, pipeline right-of-ways, or a stand-alone (remote) site that is associated with a well or pipeline.

Landspray, landspray-while-drilling, and pump-off are topsoil application methods where waste is sprayed from vacuum trucks or pumps and hoses and typically occur on fields (cultivated or vegetated) off site from the well site.

The following are descriptions of the different drilling waste management methods that are set out under Directive 050:

  1. Storage
    Water-based drilling wastes can be stored in sumps (which are earthen excavations), lined sumps, or in temporary open-topped tanks. To protect soil and groundwater quality,
    sumps can only be constructed on sites that meet the criteria for sump construction (see Section 6 of Directive 050). Hydrocarbon-based drilling wastes must only be stored in tanks.
  2. Landspread
    Drilling waste is spread over an area of the lease, incorporated into the shallow subsoil, and covered with topsoils. Testing of the wastes prior to disposal is required to determine the size of the spread area needed. The incorporation technique must provide a mix ratio of one part drilling waste to at least three parts subsoil.
  3. Mix-Bury-Cover
    Often drilling waste is stored in an earthen excavation called a sump. In the mix-bury-cover disposal option drilling waste stored in a sump is stabilized by mixing it with subsoil at a ratio of at least three parts subsoil to one part waste. Waste testing determines the ratio of mixing required. The drilling waste and soil mixture is then buried and covered with at least one metre of clean subsoil.
  4. Landspray
    Slurried water-based drilling waste or the fluid portion separated from the drilling waste
    is sprayed at predetermined application rates onto fields (cultivated or vegetated/grassland) using vacuum trucks or similar equipment. The wastes may or may not be incorporated into the topsoil. If a licensee has arranged for the landowner to incorporate the drilling waste into a field, it is important that it be done in the time indicated to avoid any potential adverse effects on the land. The area of land and application rate used are calculated based on the characteristics of the drilling waste and whether it is being incorporated into the topsoil of the field.
  5. Landspray-While-Drilling (LWD)
    LWD is similar to landspray but is limited to nontoxic drilling fluid systems. As a result, LWD has reduced testing requirements. LWD is done during or immediately after drilling operations. Disposal of drilling wastes containing hydrocarbons is not allowed by this method.
  6. Pump-off
    This method is limited to clear liquids that have separated from the water-based drilling waste within the drilling waste storage system. The clear liquids are pumped onto soils on the surface of fields or vegetated lands and are not incorporated. Testing the waste determines the rate of application and ensures that disposal criteria are met.
  7. Disposal onto Forested Public Lands (DFPL)
    DFPL is similar to both landspray and LWD, but as it involves higher application rates it is limited to application on provincial Crown land.
  8. Biodegradation
    Biodegradation involves reducing organic compounds in drilling waste through microbial processes and is most commonly used to manage drilling wastes
    contaminated with formation hydrocarbons or hydrocarbon-based drilling wastes. It can also be used to manage drilling wastes that contain other organics (e.g.
    starches, alcohols, and formates).

    The most common biodegradation techniques are land treatment and treatment within a contained system. Land treatment involves applying drilling waste to subsoil and incorporating it in so that the inherent soil processes biodegrade, transform, and assimilate the waste. Treatment in a contained system is where the drilling waste is biodegraded in an impermeable cell or on an impermeable barrier. Following the breakdown of organic compounds, the drilling waste is removed from the contained system and managed by either another land application method or sent to an approved waste management facility for further treatment or disposal.
  9. Thermal Treatment
    Thermal treatment involves heating waste in a chamber to a predetermined temperature to vapourize the organics. Once complete, vapours are captured on an adsorbent media or routed to another chamber where they are either condensed back to a liquid and captured or heated to a higher temperature and destroyed.

    Thermal treatment can effectively reduce the concentration of hydrocarbons or other organic compounds in drilling waste. Mobile thermal treatment units brought to a well site or a remote site associated with a well to treat drilling waste must be approved by or registered with Alberta Environment and Water.

Question Can all drilling wastes be applied to land for disposal?
No. Only wastes that meet Directive 050 criteria can use land application methods. In addition, Directive 050 prohibits hydrocarbon-based drilling wastes to be disposed of via landspray, landspray-while-drilling, and pump-off.

Question Are all soil types appropriate for land application of drilling wastes?
No. Not all soils can receive drilling wastes. Directive 050 sets out salinity ranges for soils that can receive drilling wastes. Licensees must sample and test soil from the fields or sites where they plan to apply drilling waste. Directive 050 also identifies limits that the soil must not exceed after a drilling waste application. These limits are designed to protect the environment and are based on Alberta Environment and Water’s soil quality guidelines. To ensure compliance, licensees must test the drilling waste to determine the amount that may be applied to an area of land. In some situations, licensees are also required to sample the soil after the drilling waste is applied to verify that the disposal has met Directive 050 requirements.

Question How often can drilling waste be applied to one area of land?
An area of land must only be subject to drilling waste disposal a maximum of twice per year: once during frozen-soil conditions (winter season) and once again during unfrozen-soil conditions (summer season).

Question When is landowner consent required for disposal of drilling wastes?
Any application of drilling waste to land in areas outside of a well site, pipeline right-of-way, or remote site associated with a well or pipeline requires landowner consent. This consent must also be obtained to take soil samples when determining if soil conditions are appropriate for drilling waste disposal.

Landowners are not obligated to consent to these activities. Licensees have the option to send the drilling waste to approved waste management facilities or manage it on the well site, pipeline right-of-way, or remote site associated with the well or pipeline.

Question Are licensees required to contact landowners before disposal operations begin?
Once consent has been given, licensees are not required by Directive 050 to contact landowners prior to commencing disposal operations. However, landowners can make this a condition of their consent.

Question What drilling waste management activities are allowed on a remote site?
Directive 050 allows wastes to be stored, biodegraded, or disposed of on remote sites. Licensees must have a written surface lease or right-of-entry agreement with landowners to develop remote sites to manage drilling wastes.
As a landowner, if you wish to restrict certain drilling waste management methods or impose conditions beyond the requirements set out in Directive 050, these details must be part of the surface lease or right-of-entry agreement.

Question What if a licensee or company doesn’t comply with requirements?
The ERCB sets out the requirements for drilling waste management in Alberta and is the government agency that has jurisdiction to ensure that industry adheres to the requirements. If noncompliance events are identified, the ERCB will require that the licensee address the problem. Licensees that fail to meet the requirements of Directive 050 may be subject to enforcement under Directive 019: Compliance Assurance.

Question Who is responsible for proper drilling waste disposal?
While environmental consultants or service contractors working for the licensee may approach landowners regarding drilling waste disposals, the proper management of drilling waste is the responsibility of the well or pipeline licensee.

Landowners with concerns about drilling waste disposal operations should discuss them with the licensee first. If unsatisfied with the licensee’s response, landowners can contact the ERCB for assistance.

Common Questions and Considerations for Licensees and Landowners Contemplating Directive 050 Land Application Methods

The following is a list of questions and considerations landowners and licensees might want to consider during negotiations around proposals to use the land application methods in Directive 050.


  • What type of drilling fluid is used at the well site?
  • What type of drilling waste disposal is proposed in the licensee’s disposal plan?
  • How much surface area will be needed for drilling waste disposals occurring off the well site?
  • Are there any constraints or restrictions on relocating the disposal site if I’m not happy with the proposed location?
  • When will the disposal operation start and finish?
  • Will agreement and recommendations on waste disposal be confirmed in writing?
  • How will the issue of compensation be handled?
  • How will licensees agree to accommodate farming or agricultural conditions and schedules in their drilling waste disposal plans?


  • Disposal operations can occur on a 24-hour basis. Therefore, discuss traffic routes that would limit noise and disturbances, safety, and soil compaction.
  • Protect vegetation against repeat applications or winter disposal.
  • Protect livestock.
  • Ensure that the disposal area is 100 metres from a water body (including dugouts) or 50 metres from a water well; has a slope of less than five per cent in summer and three percent in winter and is free of features that would lead to pooling, erosion, or migration of the drilling waste; and is not within 10 metres of ditches or property lines.
  • Protection against the spread of club root disease.
  • Drilling waste disposal may have an effect on organic farm certification.
  • Drilling waste may potentially contain radioactive tracers.