Water Quality Protection Issues for New Water Supply Wells

Transcription

1 Water Quality Protection Issues for New Water Supply Wells

2 Water Quality Protection Issues for New Water Supply Wells Project siting Facility water balance Supply well water quality analysis Supply well installation and development WQ management

3 Project siting: location, location, location Feedstock supply (corn) Transportation (rail, highway) Energy source (natural gas line) Co-products market (wet cake, dried distillers grains)? Water? Quantity? Quality? Makeup water supply alternatives? Wastewater disposal alternatives

4 Project siting: potential makeup water supply source quality Groundwater aquifers Surface waters Wastewaters Water supplies with significant amounts of dissolved materials can substantially increase the water treatment and environmental management costs for an ethanol facility (Planning and Constructing an Ethanol Plant in Minnesota: A Guidance Document)

5 Project siting: potential wastewater disposal locations WQ protection level of surface receiving waters Dry weather receiving stream flow rates Downstream lakes, wetlands Karst Existing WQ impairments of downstream waters Background WQ conditions

6 Facility Water Balance Clearly define WB upfront Makeup water supply design flow not equal to supply well pumping rate, but related Consistency between various regulatory approvals (e.g., Water Appropriations, NPDES/SDS, MDH, EAW)

7 Supply Well Water Quality Analysis: Why Design treatment processes for intended water uses Design facility wastewater treatment Design facility solid wastes management

8 Supply Well Water Quality Analysis: What Copy MPCA on all WQ data from well work collected for DNR, MDH, project proposer Specific MPCA-requested parameters ammonia, temperature, ph, specific conductance fluoride, nitrate-nitrite, total phosphorus, chloride, sulfate, sulfide, bicarbonates, alkalinity, total dissolved solids aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, mercury, molybdenum, nickel, potassium, selenium, silver, sodium, thallium, tin, vanadium, zinc (all in total form) using low-level detection Site-specific MPCA needs may be more than the list above

9 Supply Well Water Quality Analysis: Where, When Test wells Aquifer testing Other local waters testing associated with supply well work (e.g., monitoring/ observation wells, surface waters)

10 Well drilling chemicals Drill cuttings Drilling mud Erosion/sedimentation due to highvolume well water discharges

11 MDH RULES DISPOSAL OF MATERIALS. The disposal of drilling mud, cuttings, treatment chemicals, and discharged water must be according to applicable state* and local regulations. Drilling mud, cuttings, and discharged water must not be disposed in a manner that creates a health hazard. During test pumping, discharged water must be piped to a point of overland drainage.

12 MPCA RULES* NUISANCE CONDITIONS PROHIBITED. No sewage, industrial waste, or other wastes shall be discharged into any waters of the state so as to cause any nuisance conditions, such as the presence of significant amounts of floating solids, scum, visible oil film, excessive suspended solids, material discoloration, aquatic habitat degradation, or other offensive or harmful effects.

13 Dirty well water discharge

14 Dirty well water discharge

15 Dirty well water discharge

16 Dirty well water discharge

17 Dirty well water discharge

18 Avoid/minimize use of chemicals, drilling fluid additives, foams, etc. Avoid cuttings disposal where runoff to surface waters Discharge well production water to safe infiltration areas away from surface waters or direct pathways to surface waters Use sedimentation basins, mud pits, mud tanks

19 Dirty well water filter treatment

20 Lane (1955), in Rosgen (1996) Pipe clear water (aquifer test) well discharges to high-volume flow receiving streams

21 Dewatering that may have turbid or sediment laden discharge water must be treated such that the discharge does not adversely affect the receiving water or downstream landowners. Dewatering must be discharged in a manner that does not cause nuisance conditions, erosion in receiving channels or on downslope properties, or inundation in wetlands causing significant adverse impact to the wetland. The discharge points must be adequately protected from erosion and scour. The discharge must be dispersed over riprap, sand bags, plastic sheeting or other accepted energy dissipation measures. Adequate sedimentation control measures are required for discharge water that contains suspended solids.

22 More Information

23 Water Quality Protection Issues for New Water Supply Wells Project siting: WQ considerations Facility water balance Supply well water quality analysis Supply well installation and development WQ management