February 10, 2012Marcus Zbinden, Environmental Specialist III

Kellie Kish, Environmental Specialist I

Carver County’s Comments to MPCA Source Separated Organic

Compost Facility Rules

Carver County Organics Demonstration SiteArboretum Site I Mayer Site

Arboretum Site II

Site Location

Arboretum I Mayer Arboretum II

Capacity 40,000 yds at any one time

100,000 yds annually

13,000 yds annually

Material Type

Co-collected residential with large volumes of commercial accepted in year 3

Co-collected Residential and Commercial

Primarily co-collected residential with limited commercial

Management Method

Static Piles Static Piles Aerated Static Piles

Average Pile Height

20 feet 20 feet 12 feet

Distance to Neighbors

250 feet 400 feet 1,800 feet

Demonstration Site Comparison

Arboretum II (SET)

Site:• Size- 2.5 acres• Site pad – All weather surface

of 3 inches of 1½ minus limestone and 3 inches class V

• Lester Kilkenny clay loam soil Profile:

0 – 7 inches: Clay loam 7 – 38 inches: Clay loam 38 – 80 inches: Loam

• Depth to seasonally saturated soil is 12 inches

• Depth to water table is >80 inches (National Cooperative Soil Survey)

Installing Water Collection Tubes

Lysimeter Placement at Arboretum II

Site:

• Only 16% of lysimeters under piles had some liquid present but none had sufficient volume to be analyzed.

Oct. 11th - 13th: 0.74” rainfall event

Contact Water Analytical Results

(Metals)Paramete

r

Carver Co. Average

(ppm)

Landfill* (mid-range)

(ppm)

Landfill* (high-range)

(ppm)

Drinking Water Limit

(ppm)

Arsenic 3.91 500 1,700 10***

Barium 565.12 1,500 5,000 2,000

Cadmium .0025 8 70 4

Copper 11.35 30 140 1,300

Lead ND 300 1,400 15**

Mercury ND .7 2 2

Nickel 23.12 1,000 2,000 100

Selenium 3.18 500 1,300 30

Silver ND**** 40 50 30

Zinc 126.3 400 18,000 2,000* Landfill mid-range and high-range data was taken from Land Treatment of Landfill Leachate. MPCA, April 2011.** No HRL has been set for these elements as they are not found in source waters.*** The HRL for Arsenic was changed from 50 ug/L to 10 ug/L in 2006.**** Silver was sampled at ARB I and Mayer sites only.

Agronomic ConstituentsParamete

rCC Avg.

(ppm)

Landfill* (mid)(ppm)

Landfill* (high)(ppm)

Drinking Water Limit(ppm)

Nitrates 2,999 n/a n/a 10,000

Phosphorous

425.33 1,000 3,000 No HRL Set

Potassium 137,072.22**

140,000 320,000 No HRL Set

TKN 5,103.57*** n/a n/a No HRL Set

TOC 79,735 n/a n/a No HRL Set* Landfill mid-range and high-range data was taken from Land Treatment of Landfill Leachate. MPCA, April 2011.** Potassium sampled at ARB I only.*** TKN – 2 samples from ARB II were not analyzed correctly for Nitrates by PACE – both returned ND results.

Chromium & Copper

Chromium Copper0

50

100

150

200

250

300

350

CC Average

Landfill* (mid)

Landfill* (high)

Drinking Water Limit

Parameter ARB II (ppm)

Landfill* (mid)(ppm)

Landfill* (high)(ppm)

TDS 668.5 6,000,000 20,000,000

TSS ND 1,300,000 5,000,000

TDS & TSS

* Landfill mid-range and high-range data was taken from Land Treatment of Landfill Leachate. MPCA, April 2011.

(ppm

)

Residential Organics Collection

Residential Source Separated – Co-

Collected

September 26, 2011 load from Edina -Vierkant Waste Sort

Organics 2,318 lbs. 6 yards 21% (by weight) Yard Waste 8,800 lbs. 12 yards 78% (by weight) Contamination 43 lbs. .17 yards <1% (by weight)

Commercial Organics

Carver County Comments on Rules

Subp 3. B. Operator may establish a source-separated organics waste composting facility within 5 feet of water table.

Recommendation: If aquifer is that of MN Rule 4725.0100, Supb. 21, Carver County accepts rule change.

MN Rule 4725.0100, Subp. 21: “Aquifer” means a stratum of saturated, permeable bedrock or unconsolidated material having a recognizable water table or potentiometric surface which is capable of producing water to supply a well.

Carver County Comments on

RulesSupb. 8. F. The active composting, curing and storage areas for immature compost must be located on an impervious surface…

1.Contact water test results from organics demonstration sites demonstrate that there is no contact water leaving the site that exceed testing standards for drinking water.

2. Contact water levels in lysimeter installed at the demonstration site supports industry findings that compost piles absorb most moisture from rain events and allow little to enter surface water containment area or infiltrate into sub-soils.

Recommendation:• Tipping Pad - 6 inches of Class V as a minimum• Active composting, processing and curing areas – all

weather working surface which is defined as any surface that allows the ability of equipment and hauling trucks to access site for 365 days of operations.

Site Size (acres)

Class V Needed (tons)

Total Cost (Estimate:

$19.50/ton)

ARB II 2 4,840 $94,380

ARB I 4 9,680 $118,760

Mayer 7 16,940 $330,330

Tipping Pad .5 1210 $23,595

Estimated Pad Costs

1 acre = 43,560 ft2 2’ Class V to cover 1 acre = 2,420 tons

7035.2555 Subp. 3. Minimum of 500 feet horizontal separation distance from the facility to the nearest residence, place of business or public contact area.

• There is no distance requirement for either solid waste compost facility or yard waste compost facilities; there should not be a mandated distance for SSO facilities.

• Facilities vary in size, capacity, feedstock, topography and zoning.

Recommendation:• Allow local units of government to establish

distance requirements on a case by case basis. • Provide distance requirement in guidance

document.

Carver County Comments on

Rules

Compost Data Team ReportOctober 30, 2009

Background:• Data Team comprised of 4 metro county staff and 2

MPCA staff led by Allen Dotson and Geoffrey Strack.• Team was formed to complete revision of MPCA’s

Demonstration Agreement and review other state regulation on composting.

Conclusions:• Data from demonstration projects may help

answer questions regarding contamination in contact water.

• May be reasonable to provide flexibility on composting pad requirements, varying for example with site-specific soils types, feedstock types, location and scale of operation.

Recommended Tiers:I. Backyard Composter No MPCA permit or training required

II. Yard Waste Permit by Rule

III. Small Site Recommend increase to 100yds3 annually or equivalent weight

IV. Residential Source Separated V. Commercial Source Separated 0ther material as approved by MPCA

VII. MSW

• Regulation and permitting requirements become more stringent as the types or tonnages of organics material increases.o Residential co-collected sites should have reduced horizontal distance

requirement and potentially a less restrictive pad requirement. o Residential co-collected sites should also have less strict operating

procedures such as mixing material by the end of the day versus immediate cover and/or processing for commercial facilities.

Potential CompromisesAllow less stringent pad requirement and separation distance if the following conditions are met:

1. Site operator must take soil sample under processing and curing area prior to site development and periodically thereafter to ensure no contamination of ground water is occurring.

2. Facility operator could also elect to install lysimeters and take periodic samples.

3. If finished compost or contact water tests show issues, require additional testing or mediation.