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Document ID ca-bc-adsospum-2015-12 Title Assessing the Design, Size, and Operation of Sediment Ponds Used in Mining URL https://www2.gov.bc.ca/assets/gov/environment/waste-management/industrial-waste/industrial-waste/mining-smelt-energy/assessing_design_size_and_operation_of_sediment_ponds.pdf Jurisdiction /ca/bc Subdomain(s) Industrial wastewater, Stormwater, Wastewater treatment Language en Status completed Analyzed at 2026-03-15 09:48:18.632840+00:00 Relevance Technical guidance for designing and operating mining sediment ponds.

52 Qualitative 19 Quantitative 46 Definitions

Q Qualitative Requirements (52)

Req ID	Category	Intent	Legal Status	Name	Subdomain(s)	Context	Conditions	Confidence
#Q001	administrative	operational	recommended	Erosion and Sediment Control Plan Timing	wastewater, other	The MoE document titled Developing a Mining Erosion and Sediment Control Plan (Version 1; February 2015) provides detail on erosion control as well as the development of a site-wide Erosion and Sediment Control Plan. This plan should be in place prior to, or developed alongside, the detailed design of sediment ponds for a mine site.	Applicable to the development of sediment ponds.	high
#Q002	administrative	reporting	recommended	Alternative TSS Treatment Facilities Consultation	wastewater, other	If the anticipated TSS treatment facility departs markedly from the systems discussed herein, the proponent should discuss this on a case-by-case basis with MoE.	When the treatment facility design departs markedly from the sediment pond systems discussed in the guidance document.	high
#Q003	operational	operational	recommended	Implementation Supervision by Qualified Professionals	wastewater, other	Qualified professionals are also expected to supervise implementation to ensure that requirements of the plan are followed.	Applies to sediment pond design and Erosion and Sediment Control Plan implementation.	high
#Q004	monitoring	operational	recommended	Effectiveness Monitoring by Qualified Professionals	wastewater, other	Qualified professionals should monitor the effectiveness of the sediment pond and the Erosion and Sediment Control Plan, and adapt the plan as necessary.		high
#Q005	administrative	reporting	recommended	Sediment Pond Design Report Contents	wastewater, other	The sediment pond design report should include: Preliminary site assessment (e.g. site layout and size, hydrology data, soil type(s), etc.) Prediction testing Soil loss calculation - Revised Universal Soil Loss Equation RUSLE, or validated alternative predictive tool Pond inflow rates - should address seasonal variability as well as storm events. Increased volatility/frequency of storm events due to changing climate should be considered. Particle size analysis (and variations with season and flows) Erosion control upslope, as it affects pond design Design of the sediment pond Particulars of discharge frequency and duration; i.e. intermittently, purposefully when impounded water quality meets a set of defined discharge criteria, semi-continuously or continuously Vulnerability of settled solids in the pond to become re-suspended under high flow or high wind events, or as a result of ice disturbance Need for settling aids - settling aid testing (see appendix B for additional information) Settling tests on pond influent TSS - turbidity relationships Operation and maintenance o Pond discharge (flow and TSS) monitoring o Removal of sediment from the pond Inspection Reporting Company contact information	Required for a complete sediment pond design report.	high
#Q006	administrative	treatment	mandatory	Use of Settling Aids Approval	wastewater, other	Prior to using settling aids, a proponent must obtain written approval from an MoE Environmental Protection Mining Team Statutory Decision Maker.	Prior to implementing settling aids in sediment ponds.	high
#Q007	reporting	treatment	mandatory	Settling Aids Information Submission	wastewater, other	Information will need to be submitted to MoE to describe the requested approval, particularly the 96 Hour LC50 concentration of the settling aid(s) and details of the settling aid addition rate (and control method), mixing conditions, and conditioning time/facilities.	When seeking written approval for the use of settling aids.	high
#Q008	design	treatment	recommended	Flocculant Application Location	wastewater, other	If flocculants are being proposed, preferential consideration should be given to using flocculants upstream of the pond, since they require longer conditioning time than coagulants.	If flocculants are proposed as settling aids.	high
#Q009	design	operational	recommended	Use of Topographical Maps	wastewater, other	Accurate and up-to-date topographical maps should be used for the design and construction of sediment ponds, with sufficient contour resolution for design purposes.		high
#Q010	design	treatment	recommended	Pond Baffle Consideration	wastewater, other	If local topography does not allow the practical construction of a 5:1 ratio of pond dimensions, the use of internal baffles to increase the total flow path length should be evaluated.	When topography prevents a 5:1 ratio of pond dimensions.	high
#Q011	design	operational	mandatory	Dam Failure Consequence Inflow Design Floods	wastewater, other	Dams or embankments having a failure consequence of 'Significant' or greater (see consequence classifications in the BC Dam Safety Regulation and the Canadian Dam Association (CDA) Dam Safety Guidelines) must consider greater inflow design floods in accordance with the CDA guidelines.	Applies to dams or embankments with a failure consequence classification of 'Significant' or greater.	high
#Q012	administrative	operational	mandatory	Water Licence Dam Safety Compliance	wastewater, other	Additionally, sediment pond embankment structures that require a Water Licence under the Water Act must comply with the requirements of the Dam Safety Regulation and adhere to relevant specifications of the BC Dam Safety Guidelines and the conditions of the Water Licence.	For sediment pond embankment structures requiring a Water Licence under the Water Act.	high
#Q013	design	operational	mandatory	Embankment Material Appropriateness	wastewater, other	Embankments must be constructed out of materials appropriate for the application (grainsize distribution of soils, appropriate geosynthetic).		high
#Q014	design	treatment	recommended	Primary Pond for Coarse Sediment	wastewater, other	Ideally, a smaller pond should be located upstream from the main sediment pond to remove the coarse fraction of the sediment (fine to medium sand particles and greater). This primary pond should be designed to enable easy removal of sediment.		high
#Q015	design	operational	recommended	Pond Dewatering Provision	wastewater, other	Sediment ponds should be provided with a means of draining or dewatering, even if such operations are not planned during the lifetime of the pond.		high
#Q016	design	operational	recommended	Pond Clean-Out and Capacity Design	wastewater, other	Sediment ponds should either last the lifetime of the mine, including post-closure needs, without requiring removal of accumulated sediment, or should have provision for easy removal of sediment at regular intervals.		high
#Q017	design	treatment	recommended	Inlet Design Energy Dissipation	wastewater, other	The inlet works of the pond should include a means for energy dissipation (such as barriers, or baffles) to spread out the flow and reduce the velocity of the incoming runoff.		high
#Q018	design	operational	recommended	Spillway Erosion Protection	wastewater, other	The spillway should be armored to prevent erosion of the spillway channel.		high
#Q019	design	treatment	recommended	Hydrocarbon Removal Facilities Provision	wastewater, other	Also, there should be provisions in the design for installing facilities for trapping, collecting and removing hydrocarbons.		high
#Q020	design	treatment	mandatory	Effluent Quality Assessment	wastewater, other	The desired effluent quality from a sediment pond must be assessed in relation to the environmental consequences of the construction of the requisite sized pond.		high
#Q021	design	reporting	recommended	Installation of Sampling and Flow Monitoring Facilities	wastewater, other	Suitable water quality sampling and flow measuring facilities should be installed to enable monitoring of the pond inflows and discharges, if required.	If monitoring of inflows and discharges is required.	high
#Q022	monitoring	treatment	mandatory	Flocculant Influent TSS Information Requirement	wastewater, other	If settling aids such as flocculants are proposed, the effective use of flocculants requires real time information in influent TSS concentrations, typically achieved through measuring turbidity and converting to TSS based on a prior evaluation of TSS-turbidity relationships through a range of seasonal and flow conditions.	When flocculants are used as settling aids.	high
#Q023	design	treatment	recommended	Upstream Flow Measurement Facilities Consideration	wastewater, other	In addition, application rates and particulars of settling rates depend on influent flow rates, which may not track with discharge rates, so upstream flow measurement facilities should also be considered.	When assessing the effective usage rates and settling parameters of settling aids.	high
#Q024	prohibition	operational	recommended	Fish Migration Restriction Prohibition	wastewater, other	Sediment ponds should not be designed or constructed in a location where the active portion of a fish bearing stream would be incorporated into the pond design or where the pond design would restrict upstream and/or downstream migration of fish.		high
#Q025	administrative	operational	recommended	Fish Barrier Consultation for Discharging Ponds	wastewater, other	For ponds discharging into fish bearing streams, FLNRO Fish, Wildlife and Habitat Management staff should be contacted to discuss the need for barriers to prevent fish access into the sediment ponds as the chemical treatment of sediment contaminated waters or increased bioaccumulation of deleterious substances may occur there.	If the sediment pond discharges into a fish bearing stream.	high
#Q026	design	operational	recommended	Wildlife Access Prevention	wastewater, other	In general, wildlife access should be prevented as wildlife could potentially become trapped in the pond as a result of unconsolidated material in the pond or due to restricted egress due to a synthetic liner.		high
#Q027	design	operational	recommended	Wildlife Vulnerability Assessment	wastewater, other	In addition, the vulnerability of pond design (embankments, synthetic liners) to wildlife activity should be assessed and addressed.		high
#Q028	design	treatment	mandatory	Settling Aid System Provision (Method A)	wastewater, other	Provisions must also be made for the addition of a settling aid system.	When using Method A for sizing sediment ponds.	high
#Q029	administrative	operational	recommended	Water Management Plan Routing Outline	wastewater, other	In order to prevent this, it is recommended that the site Water Management Plan specifically outlines where water from each site component is to be routed if the available storage at that component is fully allocated. The plan should ensure that the highest risk sources of water are given priority, that the order of priority is clearly defined, and should lay out in table format the contributing areas for each pond so that site staff can quickly estimate the impact of re-routing water from one pond to another...		high
#Q030	monitoring	treatment	mandatory	Particle Size Analysis for Settling Aids	wastewater, other	Perform a particle size analysis to determine the settling methods that will measure the content of <10 micron 'spherical' particles which takes into account 'shape', lower particle density and other factors which tend to produce slower settling.	When determining the need for settling aids (Step 1).	high
#Q031	monitoring	treatment	mandatory	Testing Conditions Duplication	wastewater, other	The testing conditions regarding the particle surface charge, or zeta potential, must duplicate the conditions present during the operation of the sediment pond.	When assessing whether 10 micron and finer particulate matter settles naturally or requires settling aids.	high
#Q032	operational	operational	mandatory	Erosion and Runoff Management Responsibility	wastewater, other	Mining companies are responsible for minimizing erosion from disturbed areas and for collection and treatment of runoff from these areas before it is discharged into the receiving environment.		high
#Q033	administrative	operational	mandatory	Qualified Professional Requirement	wastewater, other	It is imperative that sediment pond design and Erosion and Sediment Control Plan development are undertaken by qualified professionals.		high
#Q034	design	treatment	recommended	Design Particle Capture Size	wastewater, other	MoE recommends that sediment ponds be designed to capture at least a 10 micron soil particle for the 10-year, 24-hour runoff event.		high
#Q035	design	operational	recommended	Structural Runoff Design Requirement	wastewater, other	All structures in the sediment pond system should be designed, as a minimum, to structurally withstand a 1 in 200-year runoff event.		high
#Q036	design	operational	recommended	Dam Specification Adherence	wastewater, other	All sediment pond embankment structures that are considered to be dams, based on the definition of a dam under the CDA guidelines, should be designed and constructed based on the specifications of those guidelines and the Health, Safety and Reclamation Code for Mines in BC (Code) and operated under the terms of the Mine Permit.	Applies to embankment structures defined as dams under CDA guidelines.	high
#Q037	design	treatment	recommended	Suspended Solids Removal Design Flow	wastewater, other	The minimum design flow for removal of suspended solids in sediment ponds should correspond to the 10-year, 24-hour runoff flow.		high
#Q038	design	operational	recommended	Outlet Design and Freeboard	wastewater, other	The discharge works at the outlet of the pond should be at the opposite end to the inlet section and should include an overflow spillway or other means designed by a qualified professional to maintain a minimum 0.5m freeboard, or other minimum height as noted in the applicable permit under the Environmental Management Act or Mines Act, on the embankment during the structural design runoff event (minimum 1 in 200 years).		high
#Q039	design	treatment	mandatory	Method A Supplemental Design Data	wastewater, other	Use of this simplistic design approach must be supplemented with additional information (e.g. particle size analysis, soil loss analysis, and settling tests) to confirm that sedimentation alone will achieve discharge criteria and, if not, what additional strategies will be required to reduce sediment loading into the pond and/or increase the pond's removal efficiency.	When using the simplistic design approach (Method A).	high
#Q040	design	treatment	recommended	Settling Aid Determination Timing	wastewater, other	The need for settling aids should be determined prior to the construction and operation of a sediment pond.		high
#Q041	design	treatment	recommended	Combined Settling Aid Design Implications	wastewater, other	Where there may be merits to the use of the combined and/or sequential use of settling aids, the implications for pond design and expectations regarding combined toxicity in pond effluent should be addressed in the design.	When using combined or sequential settling aids.	high
#Q042	design	treatment	recommended	Settling Aid Design Provision	wastewater, other	Provisions for adding settling aids should be incorporated into the overall design.		high
#Q043	design	operational	recommended	Additional Pond Capacity Investigation	wastewater, other	The proponent should investigate the need for additional pond capacity and retention time due to accumulated sediment volume, turbulence, and 'currents' in the pond on a project-specific basis and during operational inspection and maintenance activities.		high
#Q044	design	operational	recommended	Runoff Source Consideration for Design Flow	wastewater, other	All sources of runoff, including rainfall, snow melt, and combined rainfall-snow melt events should be considered in determining the design flow.	When determining the minimum design flow for removal of suspended solids.	high
#Q045	design	treatment	recommended	Method A Minimum Retention Time	wastewater, other	In the absence of any mitigating factors, the pond should be sized to provide not less than a 20 hour retention time for a 1 in 10 year runoff flow, and longer if the calculations above indicate it is necessary.	When using the simplistic design approach (Method A).	high
#Q046	operational	treatment	mandatory	Settling Aid Selection Process Purpose	wastewater, other	The purpose of a settling aid selection process is to: determine what settling aid promotes settling of the fine particulate; select a settling aid which has a relatively low toxicity; and, select a settling aid which achieves the discharge quality required at the lowest cost, consistent with other practical requirements.	During Step 2 of the settling aid selection process.	high
#Q047	design	treatment	mandatory	Mixing and Conditioning Requirements Determination	wastewater, other	The final step is to determine the required coagulant/flocculant mixing/conditioning requirements.	During Step 4 of the settling aid implementation process.	high
#Q048	operational	operational	mandatory	Qualified Professional BMP Proficiency	wastewater, other	The Qualified Professional will be expected to understand and apply best management practices (BMPs) related to erosion control and sediment management.	Applicable to the professional responsible for pond design and ESC plan development	high
#Q049	design	treatment	mandatory	Settling Aid Adsorption and Collision Provision	wastewater	When the settling aid is introduced to the settling system, there must be a provision to allow the particles to adsorb the settling aid and for particles to collide with other particles to allow flocs/coagules to grow.	When introducing settling aids to the system	high
#Q050	design	treatment	mandatory	Settling Aid Addition Point Upstream Location	wastewater	The addition point must be sufficiently far upstream to provide the required conditioning time determined by the laboratory testing.	When using a flow channel upstream from the pond for settling aid addition	high
#Q051	operational	treatment	mandatory	Flocculant Mixing Shear Constraint	wastewater	Low shear mixing and adequate time is necessary to achieve this. If the flocculant is added prior to a centrifugal pump, the long chain flocculant molecule is reduced in size and tends to coil back on the same particle. This prevents any further agglomeration with suspended particles and produces a particle that will not settle out effectively.	During flocculant mixing and conditioning	high
#Q052	monitoring	health	mandatory	Supernatant Toxicity Testing	wastewater, aquatic life	The key test for toxicity is performed on the supernatant fluid.	When assessing the toxicity of flocculants/settling aids in effluent	high

P Quantitative Requirements (19)

Req ID	Category	Intent	Legal Status	Name	Subdomain(s)	Limit Type	Limit Value	Context	Conditions	Confidence
#P001	design	treatment	recommended	particle size capture	wastewater, other	treatment_goal	<= 10 micron	capture at least a 10 micron soil particle for the 10-year, 24-hour runoff event	10-year, 24-hour runoff event	high
#P002	design	treatment	recommended	pond length to width ratio	wastewater, other	OG	5 to 1	preferred shape of sediment ponds is generally rectangular with the ratio of length to width being about 5 to 1		high
#P003	design	operational	recommended	structural runoff event capacity	wastewater, other	requirement	>= 200 year	structurally withstand a 1 in 200-year runoff event	As a minimum for all structures in the sediment pond system	high
#P004	operational	operational	guidance	depth of water above sediment	wastewater, other	requirement	>= 1.5 m	Normally a pond is allowed to fill with sediment up to 50% of its effective depth, with 1.5 m (minimum) depth of water above the sediment.		high
#P005	design	operational	recommended	freeboard	wastewater, other	requirement	>= 0.5 m	maintain a minimum 0.5m freeboard, or other minimum height as noted in the applicable permit	During the structural design runoff event (minimum 1 in 200 years)	high
#P006	design	treatment	recommended	retention time	wastewater, other	requirement	>= 20 hour	pond should be sized to provide not less than a 20 hour retention time for a 1 in 10 year runoff flow	In the absence of any mitigating factors	high
#P007	physical	treatment	guidance	Total Suspended Solids (TSS)	wastewater, other	MAC	< 25 mg/l	produce a pond overflow lower than 25 mg/l (or as specified in an authorization from the MoE)	Initial testing evaluating the 10 micron and finer content	medium
#P008	design	treatment	guidance	area correction factor	wastewater, other	OG	>= 1.2 multiplier	a minimum correction factor of 1.2 is suggested to account for non-ideal settling	To account for non-spherical shape of actual mineral particles	high
#P009	operational	operational	recommended	maximum sediment accumulation	wastewater, other	OG	<= 50 %	Normally a pond is allowed to fill with sediment up to 50% of its effective depth	Before clean-out is required	high
#P010	design	treatment	recommended	suspended solids removal design flow	wastewater, other	requirement	10-year, 24-hour runoff flow	The minimum design flow for removal of suspended solids in sediment ponds should correspond to the 10-year, 24-hour runoff flow.	Includes rainfall, snow melt, and combined events	high
#P011	design	treatment	guidance	assumed settling velocity for fine silt	wastewater, other	OG	2 x 10^-5 m/s	assume that approximately 5 to 10 micron (and coarser) particles need to be settled out in the pond, and that the settling velocity will be approximately 2 x 10 -5 m/s	Assuming the temperature of the fluid in the pond is close to freezing	high
#P012	design	treatment	guidance	particle sink time	wastewater	OG	21 hours	Given a minimum pond depth of 1.5 m and a settling velocity of 2 x 10 -5 m/s for fine silt, it will take 21 hours for a particle to sink to the bottom of the pond.	Assuming minimum depth of 1.5m and standard settling velocity	high
#P013	design	treatment	guidance	Stokes equation validity limit	wastewater	OG	<= 65 micron	direct application of the Stokes equation is not valid for particles larger than 65 micron	Applicable to standard Stokes equation calculations	high
#P014	design	treatment	recommended	area correction factor for flat particles	wastewater	OG	> 2.0 multiplier	correction factors greater than 2.0 are suggested by the literature if very flat particles, such as mica are present	Presence of very flat particles	high
#P015	design	treatment	guidance	settling rate correction factors	wastewater	OG	0.502 to 0.852 fraction	Factors proposed based on the lower settling rate produced by the particles not being spherical.	To account for non-spherical mineral particles	high
#P016	physical	operational	guidance	typical operating pH	wastewater	OG	6.5 to 7.5 pH units	pH of most sediment pond operation where particles possess high negative charges that prevent agglomeration.		high
#P017	chemical	health	mandatory	toxicity testing for settling aids	wastewater	requirement	96 hour LC50	Information will need to be submitted to MoE to describe the requested approval, particularly the 96 Hour LC50 concentration of the settling aid(s)	Prior to using settling aids	high
#P018	design	treatment	guidance	sediment pond area correction range	wastewater	OG	20 to 100 %	Research suggests a 20% to 100% sediment pond area correction is necessary due to the nonspherical shape of actual mineral particles	When diameters are measured by a method which does not utilize settling	high
#P019	physical	treatment	guidance	Brownian motion settlement threshold	wastewater	OG	<= 5 micron	This then results in the inability of particles of about 5 microns or smaller to settle without agglomeration or flocculation.	Due to Brownian motion impact	high

D Definitions (46)

Req ID	Name	Context	Confidence
#D001	Best Achievable Technology (BAT)	BAT is a process used to determine the best waste discharge standards based on a technology that has been shown to be economically and practically feasible.	high
#D002	Qualified Professional	a person is considered a Qualified Professional who in relation to duty or function: (a) is registered in British Columbia with a professional organization, is acting under that organization's code of ethics and is subject to disciplinary action by that organization, and (b) through suitable education, experience, accreditation and knowledge, may reasonably be relied on to provide advice within his or her area of expertise, which is applicable to designing sediment ponds and developing an Erosion and Sediment Control Plan.	high
#D003	10-year, 24-hour runoff event	maximum runoff event that theoretically occurs at a frequency of once every 10 years and lasts for 24 hours	high
#D004	Agglomerate	this occurs when the van der Waals attractive forces on particles in a suspension exceeds the repulsive forces produced by the Zeta Potential of particles in liquid suspension. Particles are then able to form clusters (agglomerules) under suitable conditions and then achieve settling.	high
#D005	Agglomeration	the action or process of gathering into an agglomerule or cluster.	high
#D006	Authorization	a permit, approval, license, pollution prevention plan, operational certificate, order, certificate, pest management plan, certificate of compliance, conditional certificate of compliance, or approval in principle.	high
#D007	Berm	see Embankment	high
#D008	Brownian motion	the phenomenon of particles in a suspension being 'jostled about' by the impact of molecules of the fluid. This then results in the inability of particles of about 5 microns or smaller to settle without agglomeration or flocculation.	high
#D009	Coagulant	an inorganic compound(s) that lowers the magnitude of the Zeta Potential allowing suspended particulates to gather together to form a cluster or coagule.	high
#D010	Coagules	masses or groups of suspended particulates effectively forming larger, settleable particles.	high
#D011	Embankment	an artificial bank, usually earthen, raised above the surrounding landscape to hold back water	high
#D012	Floc	a flocculant mass formed by the aggregation of a number of fine suspended particles.	high
#D013	Flocculant	an organic compound(s) that causes the formation of flocs, typically a long chain polymer.	high
#D014	Flocculation	a process which occurs when (usually) high molecular weight, long chain organic polymers adsorb and 'bridge' onto, and between, particles in a suspension, to produce floccules (flocs) which thereby promote settling. Agglomeration/coagulation is not necessarily a precursor to flocculation, but the two phenomena are often used together advantageously.	high
#D015	Floccule	see Floc.	high
#D016	Guideline	A numerical limit or narrative statement with respect to substances or procedures which provide policy direction on a provincial, regional or sectoral basis.	high
#D017	Standard	A legally enforceable numerical limit or narrative statement with respect to substances or procedures specified in an authorization, e.g., a waste discharge permit	high
#D018	Supernatant	A clear liquid overlying material deposited by settling, precipitation or centrifugation, such as the effluent from a sediment pond.	high
#D019	TSS Total Suspended Solids	The quantity of solid material suspended in a fluid as determined by method 0008X332 in the British Columbia Environmental Laboratory Manual, 2009 Edition on samples collected in accordance with the BC Environment Field Sampling Manual or procedure approved by a Director.	high
#D020	van der Waals attraction	The weak mutual attractive force of molecules or particles in a suspension resulting from induced electric polarization. This enables agglomeration to occur, provided the Zeta Potential repulsive force is less than the van der Waals attractive force.	high
#D021	Zeta Potential (ZP)	The characteristic of a particle's charge used to determine its ability to either coagulate with other particles or remain in a relatively stable suspended condition. ZP may be negative, zero or positive. Equipment is available to measure zeta potential.	high
#D022	Zero Point of Charge (ZPC)	The condition that occurs when the pH of the fluid containing a suspension of particles is adjusted to produce a Zeta Potential of zero. This is termed the Zero Point of Charge and occurs at a characteristic pH in a suspension of specific mineral particles. The Zero Point of Charge can also be achieved by the addition of suitable coagulants (and some cationic/anionic flocculants).	high
#D023	Ministry of Environment (MoE)	Ministry of Environment	high
#D024	Ministry of Energy and Mines (MEM)	Ministry of Energy and Mines	high
#D025	Ministry of Forests, Lands and Natural Resource Operations (FLNRO)	Ministry of Forests, Lands and Natural Resource Operations	high
#D026	Ambient Water Quality Guidelines	Ambient Water Quality Guidelines are set for parameters to ensure the protection of a given water use, including drinking water, aquatic life, recreation, wildlife and agriculture.	high
#D027	Revised Universal Soil Loss Equation (RUSLE)	Revised Universal Soil Loss Equation	high
#D028	Health, Safety and Reclamation Code for Mines in BC (Code)	Health, Safety and Reclamation Code for Mines in BC	high
#D029	sediment pond depth	the difference in vertical elevation, in meters, between the inlet water level and the bottom of the pond adjacent to the outlet.	high
#D030	Stokes diameter	the diameter of the sphere which settles at the same rate as the mineral particle.	high
#D031	TSS Total Suspended Solids (previously called Residue, Non-Filterable)	The quantity of solid material suspended in a fluid as determined by method 0008X332 in the British Columbia Environmental Laboratory Manual, 2009 Edition on samples collected in accordance with the BC Environment Field Sampling Manual or procedure approved by a Director.	high
#D032	Environmental Management Act (EMA)	Environmental Management Act	high
#D033	best management practices (BMPs)	best management practices	high
#D034	Canadian Dam Association (CDA)	Canadian Dam Association	high
#D035	critical settling velocity (Vsc)	critical settling velocity	high
#D036	Sediment ponds	Sediment ponds are for reducing sediment loadings from mine operations when other erosion control or sediment control methods are insufficient.	high
#D037	Tr	required retention time	high
#D038	V	settling velocity of 'V' metres per second (m/s)	high
#D039	Q	the 10-year 24 hour pond overflow rate in m 3 /sec.	high
#D040	A	sediment pond area	high
#D041	Vs	spherical particle terminal settling velocity, cm/s	high
#D042	g	acceleration of gravity, 981 cm/s 2	high
#D043	µ	kinematic viscosity of water, cm 2 /s	high
#D044	S.G.	specific gravity of the particle	high
#D045	D	(Stokes) diameter (cm) of a non-interacting particle measured using a settling method.	high
#D046	Vactual	actual settling velocity	high