| Introduction |
 | Ms. Faith Rossing, Director of the Department of Planning and Zoning
[QAC] |
| Mr. Jim Deiter [Program Manager, Wastewater Permits Program, MDE] |
| Dr Ching-Tzone Tien [Division Chief, Groundwater Discharge Permits
Division, Wastewater Permits Program, MDE] |
| Mr. Michael Whitehill, Maryland Municipal League |
| Mr. John Nickerson, Director of the Department of Environmental
Health [QAC] |
|
| Spray Irrigation
Systems for Municipal Wastewaters in Maryland |
| There are 30 existing spray irrigation systems in Maryland - [here
is a list] |
| Regulated under Annotated Code of Maryland §9-301, §9-303.1
(reclaimed water) and COMAR 26.08.02.09 (Groundwater Water Quality
Standards) a State Groundwater Discharge Permit is required. |
| Soil and groundwater table depth shall meet the site requirements
specified in Maryland Department of Environment Guidelines for Land
Treatment of Municipal Wastewaters |
| Wastewater must be pretreated to meet either Class I or Class II
(reclaimed water defined in §9-301) effluent quality prior to
irrigation. Two tiers of buffer zone requirements are applicable
depending on effluent quality. |
| Groundwater quality monitoring is required in the discharge permit.
Discharge to a drinking water aquifer shall not cause groundwater
water quality at monitoring wells to violate drinking water standards. |
|
| Use of
Reclaimed Water (Annotated Code of Maryland §9-303.1) |
| In general – The Department shall encourage the use of reclaimed
water as an alternative to discharging wastewater effluent into the
surface water of the State |
| Use – Reclaimed water may be used for irrigation of (1) Farmland,
(2) Golf Courses, (3) Athletic fields, (4) Turf, (5) Landscaping, and
(6) Any other use that the Department considers appropriate |
| Buffer and setback requirements – The Department may establish
buffer and setback requirements for the use of the reclaimed water
under subsection (b) of this section
 | From potable wells and surface water intakes, up to 100 feet |
| From intermittent and perennial streams and residential
structures for up to 25 feet, |
| From schools and playgrounds, up to 50 feet, and |
| From public roads and residential property lines up to 25 feet. |
|
|
| Class I and
Class II Effluent Quality |
| Class I:
| 5-day Biochemical Oxygen Demand (BOD5) < 70 mg/l |
| Suspended solids < 90 mg/l, pH 6.5 - 8.5 |
| Fecal Coliform < 200 MPN/100 ml or < 3 MPN/100 ml for golf
course irrigation |
|
| Class II (reclaimed water quality)
| BOD5 < 10 mg/l |
| Suspended solids < 10 mg/l, pH 6.5 – 8.5 |
| Fecal Coliform < 3 MPN/100 ml |
|
| Nutrients (N and P) discharge may be regulated depending on the site
location |
|
| Site
Requirements for Spray Irrigation |
| Soils
| Minimum of 4 feet depth to groundwater or bedrock, except on the
Eastern Shore where a minimum of 2 feet to groundwater table is
required |
| Moderately permeable soils (0.2 to 6 inches per hour
permeability) |
|
| Slopes
| Slopes not to exceed 15% on open vegetated lands and 25% on
forested lands |
|
|
| Buffer Zone Requirements [included in video clip above] |
| Class I effluent
| Minimum of 200 feet from the wetted perimeter to property lines,
waterways and public roads |
| Minimum of 500 feet from the wetted perimeter to houses or other
occupied structures |
| 50% reduction in distance with tree buffers |
|
| Class II effluent
| Minimum of 25 feet from the wetted perimeter to property lines,
housing structures, waterways and public roads |
| Minimum of 50 feet to schools and playgrounds |
| Minimum of 100 feet to portable [sic] wells and water intakes. |
|
|
| Storage
Requirements |
| The Permittee shall install or provide a storage facility designed
to hold treated wastewater during periods when irrigation cannot take
place including precipitation, high winds, and freezing conditions |
| Unless a facility is permitted to discharge to surface water during
inclement water, a minimum of 60 days storage is required |
| Storing 1 MGD wastewater for 60 days, a lagoon area of 37 acres at 5’
water depth (18.5 acres for 10’ water depth) is required. |
|
| Application Rate
of a Spray Irrigation System |
| The application rate of an irrigation system is determined according
to the lower value of the infiltration capacity of the soil or the
nitrogen uptake rate of the crop to be planted on the spray field. |
| The applicant shall conduct a hydrogeologic study to determine the
suitable application rate. |
| Maximum yearly average application rate is limited at 2"/ wk (Per MDE
Guidelines) |
| For 1 MGD wastewater irrigation at 1” wk rate and 60 days storage
time, an irrigation area of 340 acres is required. |
|
| Effluent
Quality and Buffer Limitations (Examples: Centreville and Riddle Farm
WWTPs) |
|
| Monitoring Requirements Centreville Spray Irrigation System
[included in video clip below] |
| Effluent qualify monitoring (prior to spray irrigation) - Take one
sample weekly and analyze for BOD, suspended solids and fecal coliform
while pH is measured daily. |
| Ten (10) wells for groundwater quality monitoring. Three (3)
surface water monitoring stations along tributaries of Three Bridge
Branch.
| Take one sample every three months after start-up; and |
| Analyze groundwater and surface water samples for nitrate, pH,
total phosphate, total dissolved solids, chlorides and fecal
coliform |
|
| Daily logs and monitoring reports
| Record: 1) area irrigated, 2) application rates, 3) field
responses and 4) weather conditions. |
| Submit monitoring reports quarterly to MDE. |
|
|
| Operational
Requirements Centreville Spray Irrigation System |
| No spray irrigation on areas with bare unvegetaged soils |
| No spray irrigation during periods of precipitation, high winds,
freezing conditions or saturated soil |
| No surface runoff or ponding from excess irrigation |
| The annual average irrigation rate not to exceed 0.3”/wk (fields
7,8,9), 0.5”/wk (field 2), 0.6”/wk (field 4), and 2”/wk (fields
1,3,5,6), total irrigation area 223.7 acres |
| Daily operational parameters including irrigation application rate
and weather conditions, etc. to be reported. |
|
| Effects
of Irrigating Treated Municipal Wastewater on Soils |
| Effect of heavy metals in wastewater
| Heavy metal concentrations in municipal wastewater are typically
low and will not be accumulated onto soils to reach a harmful
level for a long time (736 years from Cecilton Data) |
|
| Effect of sodium in wastewater
| Sodium concentration in municipal wastewater are typically low
(40-70 mg/l, 74.5 mg/l for Cecilton) and will not cause dispersion
of clay particles to reduce soil permeability. |
|
| Industrial discharges, if any, should be evaluated on a case by case
basis
| Example: ConAgra Food Spray site at Queenstown used Gypsum to
restore soil permeability due to high sodium (>660 mg/l)
wastewater. |
|
|
| Example:
Prince Fredrick
(click on a slide for a more readable version)
|
Prince Fredrick
No2 WWTP, SBR - Aeration (Design Capacity: 300,000 gal/day
|
Prince Fredrick
No2 WWTP, SBR - Settling
|
Prince Fredrick
No2 WWTP Chlorination Tank
|
| Prince Fredrick
No2 WWTP, Storage Pond (60 days)
|
Prince Fredrick
No2 WWTP, Spray Field
Monitoring Well (10 wells total)
|
Prince Fredrick
No2 WWTP, Spray Irrigation Field (55 acres and 1.7"/wk irrigation
rate)
|
| Example:
Cobb Island
(click on a slide for a more readable version)
|
Cobb Island Aerated Lagoon
(158,000 gal/day)
|
Cobb Island
Aerated and Storage Lagoon (90 days storage time)
|
Cobb Island Spray
Irrigation Field (Reed Canary Grass Planted, 26.2 acres)
|
Cobb Island Spray Irrigation
Field (Cuckold Creek Site) (26.2 acres)
|
| Cobb Island Spray Field -
Cuckold Creek Site Monitoring Well (total 5 wells)
|
Center Pivot
Spray Irrigation minimizes interference to farming activities
|
Standing Water
Accumulated on Tire Track of a Center Pivot System (Place gravel on track
will abate problem)
|
Excessive Irrigation Can
Cause Ponding Water
|
| Centreville
Update |
Remember that this was presented on April
13th, which was after Terry Adams was placed on administrative leave and
two days before Mary McCarthy was sworn in. |
