GEOTHERMAL HEAT PUMPS: CONCEPT TO COMPLETION Review of New England Regulations For The Installation And Operation Of Geothermal Heat Pump Wells Instructors:

GEOTHERMAL HEAT PUMPS: CONCEPT TO COMPLETION

Review of New England Regulations For The Installation And Operation Of Geothermal Heat

Pump Wells

Instructors:Paul BlainJoe Cerutti

MassDEP – Drinking Water Program

The Thermodynamics of It All

Do GSHPs Work in Cold Climates?

Coefficient of Performance (COP) = Heat Energy Output

Electric Energy Input

Industry claims COP ranging from 3 to 6

From the Carnot cycle:

COP theoretical limit =

Indoor Temperature

(Indoor Temperature - Temperature of heat source/sink)

MassDEP

Thermodynamics (continued)

Example:

• Heat a dwelling to 70 °F ~ 294 °K

• Ambient groundwater temperature in Massachusetts is typically about 54 °F ~ 285 °K

From the Carnot cycle:

COP theoretical limit = 294 °K = 33

294 °K – 285 °K

MassDEP

Thermodynamics (continued)

What happens to the theoretical efficiency toward the end of the heating season if the entering water temperature has dropped to 35 °F?

35 °F ~ 275 °K

COP theoretical limit = 294 °K = 15

294 °K – 275 °K

MassDEP

Abbreviations and Definitions:• UIC = Underground Injection Control• GSHP = ground source heat pump = geothermal heat pump• DX = direct exchange (ground portion of heat exchange occurs

across a refrigerant loop)• Dual use well = a well that is used as both a source of drinking

water and heat pump supply • Return flow = majority of the discharge from an open-loop heat

pump• Bleed flow = typically is 5% to 10% of the discharge from an open-

loop heat pump that is not returned to the standing-column well• gpd = gallons per day• gpm = gallons per minute

• Know the regulations for your state

• Each of the New England states has a unique set of permitting, construction, withdrawal, and discharge requirements for geothermal heat pump wells

New Hampshire Department of Environmental Services (NH DES)

• UIC registration required for all open-loop and closed loop systems– individual registration form for single family residence– other registration form for all other types of facilities

• Annual water quality monitoring requirements for open-loop wells

NH DES (continued)

• With the exception of system bleed discharges, the following is not allowed:– withdrawal from aquifer and discharge to surface

water– return flow to open-surface-infiltration

NH DES (continued)

• Dual use not allowed for anything other than residential (1 to 2 units)

• Water Well Board requires a drilling license for the installers of closed-loop and DX wells

• Standing column return flow must be at least 50 feet below operating water level in well

NH DES (continued)

• > 20,000 gallons in any 24 hour period averaged over 7 days, requires Water Use Registration– applies to all open-loop wells (includes standing

column with no bleed)

NH DES (continued)

• > 57,600 gpd (40 gpm) design return flow plus bleed volume discharge requires both a Large Groundwater Withdrawal Permit and the development of a Water Conservation Plan– eligible for waiver if actual return flow (including

system bleed) doesn’t exceed 57,600 in any 24-hour period

– also eligible for waiver if can demonstrate that water is returned to same aquifer

• withdrawal from bedrock aquifer and discharge to overburden aquifer is generally considered returning to same aquifer

NH DES (continued)

• Open-pond loop not allowed unless applicant owns 100% of the surface water body

Maine Department of Environmental Protection (ME DEP)

• UIC registration required for both open- and closed-loop wells

• Open-loop– recommend heat exchanger to reduce threat of

refrigerant release into the well in the event of a failure in the heat pump

• Closed-loop antifreeze – propylene glycol– grouting recommended

ME DEP (continued)

• DX– grouting recommended– cathodic protection recommended

• Open-Pond Loops– banned in Class A surface waters (nearly all of

Maine’s surface water bodies are considered Class A)

ME DEP (continued)

• Where PE license required, UIC registration is also required

– required for design of commercial GSHP systems if includes multiple heat pump units or if any unit exceeds a maximum cooling capacity of 5 tons or heating capacity of 200,000 BTUs

– exemptions for 1 to 2 family residences and farm buildings with overall floor plan </= 3,000 square feet

ME DEP (continued)

• If discharging anywhere but to the same standing column well or municipal sewer system requires the following raw water laboratory analytical results from each supply well (unless can demonstrate hydraulic connection):

• If supplying well with make-up water from a different source, that source must also be tested for the above

• Recommend testing for lead and copper 90 to 120 days after system start-up unless using a heat exchanger ahead of the heat pump

• VOCs (EPA Method 8260)• Diesel range organics• Gasoline range organics• Arsenic• Lead • Uranium

• Sodium

• Chloride

• Manganese

ME DEP (continued)

• Well Driller Program– requires that well drillers fix any problems associated

with improper well construction– require drilling and blasting rig operators to obtain a

license to install GSHP wells– registered drillers required to take a 2 to 3 day training

course for GSHP certification (many existing drillers grandfathered)

• Additional changes expected in 2010– currently working on well construction requirements

including grouting requirements and setback distances for closed-loop and DX wells

Vermont Department of Environmental Conservation (VT DEC)

• UIC Program– only open-loop wells are required to obtain a UIC

permit– up to 25,000 gpd use eligible for a general permit but

only if returning to the same aquifer– > 25,000 gpd must obtain an individual permit– administrative fee, review fee, and annual operating

fee apply to both the general and individual permits– temperature is the only water testing requirement– VT’s UIC regulation are currently being revised

VT DEC (continued)

• Groundwater Withdrawal Permit– Exemptions for:

• residential use• closed loop or standing column

– Existing groundwater withdrawals• > 20,000 gpd (~14 gpm) withdrawal averaged over one

month must file a groundwater report indicating the capacity, frequency, and rate of the withdrawal

VT DEC (continued)

• Groundwater Withdrawal Permit (continued)– New groundwater withdrawals beginning July 1, 2010

• No new withdrawals of >57,600 gpd (40 gpm) for commercial or industrial uses without first obtaining a Groundwater Withdrawal Permit through VT DEC

• For existing withdrawals of >57,600 gpd (pre-July 1, 2010) increases in withdrawals of 25% of existing or increases of 57,600 gpd (whichever is smaller) requires a permit

– based upon highest historical use from 2005 – 2010

• Permit process includes public notice and public meeting requirements

VT DEC (continued)

• VT requires permitting of private drinking water wells - dual use of private drinking water wells are handled differently in each region

• Well Driller Program– well construction requirements apply for wells greater

than 20 feet deep

Connecticut Regulations

Connecticut regulations regarding GSHP wells are administered by several state agencies

• Department of Environmental Protection• Department of Public Health• Department of Consumer Protection

Connecticut Department of Consumer Protection (CT DCP)

• DCP has jurisdiction over the well drilling code– recently attempted to pass GSHP regulations for

open-loop, closed-loop, and DX wells but rejected by the state legislature

– currently GSHP requirements are determined at the individual town level

Connecticut Department of Public Health (CT DPH)

• Establishes set back distances for open-loop wells (same requirements as for private drinking water wells)

• Recommend that local boards of health require permits for closed-loop wells

Connecticut Department of Environmental Protection (CT DEP)

• DEP UIC Registration of discharge of Minor Heat Pump Water required for– groundwater discharge of >/= 5,000 gpd and up to

50,000 gpd• Monitoring required for lead, copper, zinc, oil & grease, & pH• Monitoring frequency = Semi-Annually• Discharge limits of pH = 5.0 – 9.0, and no visible oil sheen

CT DEP (continued)

• UIC registrations (continued)– Surface water discharge of >/= 50,000 gpd and up to

500,000 gpd• Monitoring required for lead, copper, zinc, pH, temperature,

chlorine, salinity, hardness, and aquatic toxicity• Monitoring frequency = Semi-Annually• Discharge limits for pH, temperature, salinity, aquatic toxicity,

and no visible oil sheen, floating solids, discoloration, or foaming

• Exemption for residential GSHP discharge

– No chemical additives allowed for UIC registration

CT DEP (continued)

• DEP Groundwater Withdrawal Permit– Required for any groundwater withdrawal > 50,000

gpd unless returned to same aquifer within 250 feet from the withdrawal point

Rhode Island Department of Environmental Management (RI DEM)

• UIC permitting only required for non-residential open-loop GSHP wells– Setback distances are shown on the UIC application

form

Massachusetts Department of Environmental Protection (MassDEP)

MassDEP regulates geothermal heat pump wells, withdrawals and discharges under the following programs:

• Underground Injection Control (UIC) Program• Well Driller Certification Program• Water Management Act Program• Groundwater Discharge Program

History of UIC Requirements for Ground Source Heat Pump (GSHP) Wells

• May 1982 – MassDEP requires Underground Injection Control (UIC) registration of GSHP wells

• 1986 – EPA confirms state UIC programs’ ability to regulate closed-loop (including DX) GSHP wells as Class V wells

• 2003 – MassDEP issues a GSHP fact sheet (posted on Well Driller Registration Program’s web site)

• Late 2007 – MassDEP begins process to develop GSHP well guidelines

• February 2009 – MassDEP adopts Guidelines for GSHP Wells

• March 2009 – minor revisions to guidelines• February 2010 – elimination of registration fees and

significant reduction in UIC application submittal requirements for closed-loop & DX wells

MassDEP

What Wells Require a UIC Registration?

• Any well receiving return flow or system bleed from an open-loop system

• All closed-loop and Direct Exchange (DX) wells

Note: UIC registration is required for all of the above unless a Groundwater Discharge Permit (GDP) is required.

MassDEP

What Wells Are Excluded from Obtaining a UIC Registration?

• Open-Loop if: - raw water exceeds primary drinking water Maximum

Contaminant Levels (MCL) (may require a Groundwater Discharge Permit (GDP))

- any chemical addition requires a GDP- drawing water from a Public Water System (other than

make-up fluid)

• Any GSHP well if using any material or additive not discussed specifically in the guidelines- May require a pilot test installation

MassDEP

Responsibilities

• Owner/Operator - properly operate and maintain system and notify UIC Program of changes to registration information

• Designer – MA PE or certified by International Ground Source Heat Pump Association (IGSHPA), Canadian Geoexchange Coalition (CGC), or the equipment manufacturer

• Installer - certified by International Ground Source Heat Pump Association (IGSHPA), Canadian Geoexchange Coalition (CGC), or manufacturer

• Well Driller - regardless of well type must be a Massachusetts Certified Well Driller

MassDEP

Setback Distances

If the open-loop well is also a private water supply well then all standard setback distances apply

All others:• 25 feet from potential sources of contamination including but not

limited to: – septic tanks/fields– lagoons– livestock pens– oil or hazardous materials storage tanks

• 10 feet from property boundary (some towns require further setbacks from public road)

Closed-loop and DX wells:• 50 feet from private drinking water wells

MassDEP

Open-loop wells must be installed per the standards established in the MassDEP Private Well Guidelines

• Bedrock Wells: casing set a minimum of 15 feet into competent bedrock and grouted in place

• Overburden Wells: grout seal across any confining layers and grout seal at or near ground surface

MassDEP

Grouting Requirements

Grouting Requirements Continued MassDEP

• Closed-loop: Due to concerns associated with the expansion/contraction of plastic tubing (HDPE), high solids bentonite slurry grout required:

• DX: Same grouting requirements as closed-loop but a cement-based grout may be used in place of bentonite slurry grout

• Note: sand/bentonite mixture grouts (thermal grouts) are acceptable as long as the cured grout’s hydraulic conductivity does not exceed 10-7 centimeters per second.

Grouting Requirements Continued MassDEP

Grouting Requirements Continued

• Closed-loop: Due to concerns associated with the expansion/contraction of plastic tubing (HDPE), high solids bentonite slurry grout required:

• DX: Same grouting requirements as closed-loop but a cement-based grout may be used in place of bentonite slurry grout

• Note: sand/bentonite mixture grouts (thermal grouts) are acceptable as long as the cured grout’s hydraulic conductivity does not exceed 10-7 centimeters per second.

MassDEP

Grouting Requirements (continued)

Allowable Additives

• Open-loop: no chemical additives currently allowed under UIC registration (GDP required)

• Closed-loop: propylene glycol and ethanol• DX: R-22, R-407A, and R-410A refrigerants,

food grade lubricating oils, and polyol ester

MassDEP

Other Requirements

• All GSHP wells: leak detection and emergency shut-offs– for closed-loop these are required for leaks in both

the water loop and the refrigerant loop

• Open-loop: discharge below the operating water level in the well

• DX: cathodic protection (some exceptions)

MassDEP

Other Requirements (continued)

• Dual use as a Private drinking water well - cross connection device prior to the heat pump - BOH approval for Private Drinking Water Well- requires local plumbing inspector approval (currently some will

not approve dual use wells)

• Make-up water from Public Water System (PWS)- approval from PWS - backflow prevention device at PWS connection to building and

2nd device just prior to GSHP heat exchanger- MassDEP does not allow automatic feed systems

MassDEP

MassDEP


- Local approval of bleed discharge to municipal sewer or stormwater

- Water Management Act Form I – determination of non-consumptive use- required for system design rate > 100,000 gpd (70 gpm)

- (current version of guidelines references 75,000 gpd (52 gpm))


• Construction Dewatering - must apply for approval (UIC or NPDES)

• Working within a wetland or surface water buffer (check with local Conservation Commission)

• Some BOH have adopted their own GSHP regulations and BOH permits may be required for some or all of the GSHP categoriesNote: BOH may adopt stricter standards than MassDEP and BOH may exclude certain types of GSHP wells

MassDEP

MassDEP

Open-Transfer Well

Open-Transfer Well: > 5% of return and/or system bleed is discharged to a different aquifer.

These wells require the submittal of a justification statement with the UIC registration package.

Massachusetts Health Officers Association Annual Conference

Proposed Guidelines Changes

All GSHP wells:

• 10-foot setback from water and sewer lines

Open-loop wells:

• 25-foot setback from other potable water supply wells• Backflow prevention on system bleed line

Dual use (potable water supply and GSHP discharge) wells:

• Return flow discharge must be located above pump withdrawal depth

MassDEP


All GSHP wells:


Open-loop wells:





All GSHP wells:


Open-loop wells:




MassDEP

Guidelines Changes

All GSHP wells:


Open-loop wells:




Figure copied from UIC submittal from GeoHydroCycle, Inc.

MassDEP

New Technologies Under Consideration

Concentric Closed Loop

• Consists of an inner and outer well casing- Inner casing is essentially a drop tube open ended just

above the bottom of the outer casing• Use of experimental well casing and grout materials with better

thermal conductivity values• UIC Program will treat similar to conventional closed-loop

- Same set-back distance requirements- Same antifreeze solutions

MassDEP

Issues Under Consideration for Future GSHP Guidelines and Well Driller

Regulation Changes

• Review exceedances of secondary drinking water standards

• Consider establishment of different sets of raw water sampling requirements for open-loop wells depending upon regional setting, geologic setting, and land use

• Consider establishing a special classification for well drillers that only install DX wells or DX & closed-loop wells

UIC Registration Application Process

Closed-loop and DX: UIC Registration Application for Closed-Loop Ground Source Heat Pump Wells

Residential up to 4 household units: BRP WS06e – fee exempt

All others: BRP WS06a,b,c – fee applies unless applicant is a municipal government

MassDEP

What Is My Well Type & Application Fee for a BRP WS06a,b,c application?

06c - five (5) or fewer wells with no well exceeding a well depth of 750 feet

- well type = 5A7- fee = $90

06b - more than 5 wells, or one or more wells exceeding 750 feet in depth

- well type = 5A6- fee = $240

06a - does not apply to GSHP well registrations

MassDEP

Application ProcessClosed-Loop and DX Wells

1. Submit application package prior to well installation

2. MassDEP issues UIC registration number for well installation and system start-up

Note: Any installation that will use materials, chemicals, or refrigerants that are not discussed in the guidelines require prior approval from the UIC Program.

MassDEP

Application Process Open-Loop Wells

Additional steps for open-loop wells:

1. After obtaining UIC registration number and installing the well, applicant submits raw water analytical results

2. MassDEP approves raw water quality results

3. Applicant submits post heat pump bacteria results

4. MassDEP issues system start-up approval

5. 90 to 120 days after system start-up, applicant collects a post heat pump water sample and submits analytical results for lead and copper to MassDEP

6. MassDEP issues final approval letter

MassDEP

Open-Loop Application (continued)

• Site Plan

• Cross Section of GSHP well and bleed well (if applicable)

• Design rate of system and of bleed well and anticipated bleed volumes (daily maximum and total annual)

MassDEP


Site Plan (Title 5 plans as base map are preferred) including:• GSHP well location• GSHP bleed well location (if applicable)• location of supply and return lines• footprints of building structures• location of septic tank and leach field• property boundaries• locations of any nearby drinking water wells (including

abutting properties)

MassDEP


Cross section of proposed well construction including:• well depth• boring diameter• tubing diameter & material• grout interval• grout material• depth of supply/return lines to wellhead• include cross section of bleed well (if applicable)

MassDEP


Raw water analytical requirements:

MassDEP

• VOCs (EPA Method 524 + MTBE)• Arsenic• Nitrate (As N) • Nitrite (As N)• Perchlorate• Gross alpha radiation• Radium (226 + 228) • Uranium

• Sodium

• Chloride

• Corrosivity

• Iron

• Manganese

• pH

Notes: Radium(226 +228 only required if gross alpha =/> 5 pCi/L

Uranium only required if gross alpha =/> 15 pCi/L

MassDEP raw water testing requirements typically exceed local BOH

Open-Loop ConcernsMassDEP

Open-Loop ConcernsOpen-Loop ConcernsOpen-Loop Concerns

• Unacceptable post heat pump lead and copper results– water chemistry– electrolysis resulting from insufficient grounding of

the electrical system

Lessons LearnedOpen-Loop Wells

Slide copied from Water Energy Distributors, Inc.


Open-Loop ConcernsOpen-Loop ConcernsOpen-Loop Concerns

• Coastal Environments – salt water intrusion and contamination of fresh water

aquifers– corrosion concerns for plumbing and heat pump

equipment

Lessons LearnedOpen-Loop Wells (continued)

NOT TO SCALE

Available drawdown for extraction

Available depth to water for injection

Ratio of injection wells to extraction wells may be 2:1 to 4:1

Withdraw-Recharge Systems


Open-Loop ConcernsOpen-Loop ConcernsOpen-Loop ConcernsLessons Learned

Open-Loop Wells (continued)

• Open doublet: pressurization of injections well– It’s typically a lot easier to pump water from a well than it is to

inject– 1 psi of pressure at the wellhead = 2.3 feet of water column– 10 psi of pressure = 23 feet of water column– What can happen if I pressurize the injection well?:

• Break-out of ground water at ground surface resulting in flooding and the icing of walkways, roads, and driveways in the winter

• Blow-outs or sink holes and the resulting concern for the structural integrity of nearby roads and building structures and damage to landscaping features

MassDEP

• Open doublet (continued)– Consideration: A 1,000 foot deep well that is capable of

producing 20 gpm with 300 feet of drawdown probably can’t receive an injection rate of 20 gpm if the operating water level in the well is significantly shallower than 300 feet without pressurizing the wellhead.





MassDEP



Lessons LearnedOpen-Loop Wells (continued)

MassDEP

• Electronic filing (eDEP) system for UIC applications is being launched this year

• Paper forms and instructions will also be updated

Changes to UIC Registration Process

MassDEP UIC Information & Contact

Guidelines for Ground Source Heat Pump Wells & UIC forms and instructions available on MassDEP’s UIC Web page:http://www.mass.gov/dep/water/drinking/uic.htm

For GSHP UIC Registration:

Joe Cerutti – [email protected]

MassDEP

Documents

GEOTHERMAL HEAT PUMPS: CONCEPT TO COMPLETION Review of New England Regulations For The Installation And Operation Of Geothermal Heat Pump Wells Instructors: